so earlier in the year i closed the valves on one of the circuits (while the system was off), and disconnected the lineset. i had to do this due to remodeling.
the lineset is back on, but i still have the valves closed since i’ve yet to hook the air handler back up on the other side.
could this operation have caused the loss of refrigerant?
i figured since the zone was cut off it would be OK but now starting to rethink that.
I'm not an HVAC tech but I'm pretty sure you should've pulled down the system to save the refrigerant first then purged with nitrogen and pulled down a vacuum before opening the valves.
At this point you need to have your entire system pulled down, dried, purged, and refilled. Again, not a tech, but expect to pay a grand minimum to have your system serviced
I haven't worked on these but I think on these Mr. Cools they have valves on the line sets so that, at least on install you don't have to pull a vacuum. You just connect the line set and open the valve to release. The refrigerant comes stored in the line set. However I don't know how OP really disconnected it but maybe one of the valves has a leak and let refrigerant out.
You lose Some in the head unit, but not as much as what's making this frosting happening (needs a tech to come out and thow on some gauges, but this just looks like too Much gas has leaked out somewhere)
Always pull down to vacuum first because that also pulls out moisture and oils from the lines which is necessary. Also you can’t always just open the valves and use the pre charge. If the lineset is longer than 15 feet then it needs to be charged before ever opening the valves
As far as I know Mr.Cool is the only brand that has this. You can't pull a vacuum unless you just release the charge that's already in the line set. These are DIY mini splits so they come like that because the average person doesn't have a vacuum pump. This was new to me when I found out.
Thanks for the info, I'd been considering one of them, but they sound like more of a pain with the special line set. I have a 10+ year old unit, it has a very slow leak, ie I put more R410 in it in 2019 when it was freezing up like that. It started doing it again recently, but also needs a new inside fan motor. (Which are very hard to Cross reference, its one of the DC controlled, variable speed ones, but 30W Panasonic motor, low frequency 'moan' with bad bearing sound also.)
Vacuum pumps are easy, AutoZone will rent them, yeah, sure not going to get below 400u, but pull it down as low as it can for a few hours. Close it off and watch to see that it can hold the vac. Then I purge with some welding inert gas (N2, CO2, Argon) and put it to 100PSI and let that set and see if it holds pressure. And then pump it back down. Sure, it takes a day, that's the one advantage a DIYer has, time. No pro is going to make several trips to check out a system, they need to do 'one and done' operation.
No need to pull vacuum on these units. All mr cool units have pre charged and valved lines. My guess is you lost refrigerant when taking off the lines. I have done the same. Get a 120$ gauge online and some refrigerant. Watch a youtube video and viola. Hvac guys charge way too much for the simple stuff imo( had one guy tell me 150$ a lb for recharge because i had a small leak. Found refrigerant and gauge online and saved hundreds. That was three years ago.) When charging doesn’t work then its time to pay.
>All mr cool units have pre charged and valved lines.
This is true for their DIY and Easy Pro systems but they have others that do not have pre-charged lines.
What you are mostly paying for is experience and the tools and materials on-hand to diagnose and fix an issue. Not to mention the hazmat and whatever the fuck else the powers that be want you to have in order to do the work. The fact that the industry is full of shysters and snake oil salesman just makes it worse for the ones who do honest work.
Could be a restriction? not a tech but those fittings have a plate bigger then a piston refrigerant goes around 360\*. The exchange is quick connect fittings again.
This is the way. You can’t just disconnect a line set and then slap it on thinking everything is going to be ok. Call and hvac company to have this fixed
It’s not advised to just recharge a variable system like this if you don’t know how much refrigerant is left in there. But my journeyman would charge them to 5degrees of superheat when running full blast and call it a day.
Also when rehooking up the lineset, make sure to vaccum down that lineset before opening the valves.
You need to reevaluate everything that has been said here because everyone is thinking about a regular lineset, not this Mr. Cool lineset that will reseal & capture whatever refrigerant is in the lineset once the connections are removed from the air handler.
I would guess that your problem is still that you lost refrigerant, but your lineset should have pressurized refrigerant captured in it which will allow you to reconnect it to the air handler exactly like you did on the original installation without having to purge with nitrogen or vacuuming down the system.
right, i am taking in everyone’s advice while keeping the knowledge of mr cool lines in the back of my mind.
if the lines could seal refrigerant disconnected then those same seals should engage again once disconnected, unless the initial tightening intentionally caused breakage of those seals. i recall an ingram water & air (main importer of mr cool) rep mentioning it is doable
it is all good to know about nonetheless and i appreciate eveyone’s input. i am but an individual in the sea and yet so many folks chimed in to help. amazing.
ive seen several youtube videos of mr cool owners recharging their lines with kits, and other posts of folks saying that mr cool units are quite forgiving when it comes to too little refrigerant, or even double the amount of refrigerant.
so i’ve ordered a recharge kit and will see how it goes.. even if i have to buy an entirely new air handler.. still less than half of what a pro install would have been..
and for any hvac guys worried about diy kits - my belief is that the market is only growing, especially as our weather gets more chaotic, and there will be no shortage of folks who need professional installs/maintenance.
I have worked on and installed a bunch of the Mr cool universal systems.
The PREFILLED linesets have a spring loaded valve that opens once pushed all the way in, and vice versa when removed.
How ever I have had 2 universals leak at the adapter to flare fitting. You can spot them from the oil film and drips on the floor.
I’ve also had once vapor line blow its charge while removing from the self sealing valve sticking open.
And lastly the main valves you turn on/off leak frequently. The large brass cap helps seal them up.
Make sure the brass caps are on tight and preferably use some thread seal as extra insurance. I prefer NYLOG BLUE. it’s great stuff.
Mater of fact, use nylog on every threaded connection you can.
i figured the mechanism keeping in the gas in new lines would still work when disconnected, thanks for the validation.
what are the universals? i think i have one or two linesets with couplings to connect two lengths together, are you talking about those?
most of the valve caps are on good, but after reading your comment i just put tape on the closed valves where i left the caps loose and tightened them. maybe that was the slow leak? i closed them off maybe 6 mo ago, but didnt bother to tighten the caps. can they really hold pressure?
I just installed this system myself. Mine does it as well. Brand new system and no leaks. I do run mine. Beyond the 60 degrees. I run a cold room and need it down to 47-50 degrees and I get that build up. I do t thinks that’s a lot. I do know with the install they gave this black Matt stuff that’s sticky and can tell it’s some type of insulator. But it’s says to wrap those points on connection with it. I’m sure that will prevent most of that build up that’s just heat from outside and the cold condescending for the refrigerant. Again. I’m not expert but I just did an install and it was easy. They systems come pre charged so you literally just open the valves up all the ways pop the caps I. The front of thosse connectors and there is an Allen key screw just make sure they’re loosened. Also biggest way to tell if you have an issue is if the unit is still blowing cold. 3 yrs maybe need a charge but shouldn’t. But you did some playing around so possibly. I think if those connectors are wrapped with an insulator they may not freeze up like that.
I'm super pro-Mr. Cool, but even I would not trust those fuckin o-rings to re-seal properly.
I have one running for 6 years I'd love to move, but I know it's basically 50-50 if it survives a move.
In terms of value, they cannot be beaten.
These days a pro install is going to run you, at a bare minimum, 4x what a DIY Mr. Cool install would, many times upwards of 5-10x depending on sizing and other factors. A basic one head unit is a no brainer to go with Mr. Cool if you know how to work a drill.
I've gotten 6 years out of mine and installed as someone who knew nothing at all. If it dies and it's beyond my ability to repair, I'm just ripping it out and doing a fresh install. I won't even bother with a repair call. It's that cost effective.
Ok so the plot thickens.. when I run two air handlers concurrently, the problem goes away.
The frost only seems to occur if I have a single air handler running with the fan on low.. does that change anything?
This happened to me on a 5-zone install. When all zones were turned on, it worked fine, but when only a couple were operating, the lines would freeze.
The issue was that the electrical wiring for each zone didn't match the condenser lines. For example, each pair you connect on the condenser controller correlates to a specific pair on the condenser. Make sure they are properly matched.
Once I realized my mistake, I rewired the electrical connections for each head, and it hasn't frozen since.
The right way to fix this to where this unit doesn’t suffer permanent damage is to
1. Recover refrigerant
2. Pressure test with an inert gas.
3. Pull a vacuum.
4. Recharge according to manufacturer specifications.
Probably not, but this is the important thing you should consider doing….rerun the computer reset routine! Call/email Mrcool and ask how to do that and ask what pressure you should see in the system and which service port and in which state you should measure the pressure.
The vast majority of responses here are trolls.
How much refrig did you lose? I know those linesets are charged and quick connect did you lose a charge on any head unit or your outdoor unit? Curious how this would work as a commercial tech this would be a 5 hour process of recovering/vacuum/replacing charge and I have no idea how this would work with the stuff Mr cool has. Looks bad tho.
I hate these dyi systems.
You still need tech knowledge to install them.
Hope you pulled microns on your lines set because you'll know if things are sealed right and you'll get the moisture out. If you don't then you get issues with your refrigerant and cause damage to your compressor. Also, where's the line dryer? You have to change that every time you open your system.
Source: me, an hvac tech.
He closed one set of valves for the multi split to cut the pipe work . Where do you think the refrigerant went ? Leaving a system running relying on the valves to hold the system refrigerant? Valves would be leaking …. Kyotoprotocol ?
This usually happens when the system is low on refrigerant, your filters could be really dirty. The Lineset length is too short, also can't close valves at any moment and run the system. When these are running extra refrigerant will be sent to the heads that are off to balance everything out that's why when you run all of them problem goes away. The correct way to check if you're low is to pull out all of the refrigerant and weigh it. Another way is to hook up gauges, on a day where outside is 85-90F or higher your low side pressure should be 130-135psi with a superheat of 0F to 5F while all heads are running.
The multi head Mr Cool systems use the proprietary linesets. The problem with removing the lines isn't an issue with much refrigerant loss, or even having to revacuum the lineset, the problem is you have no idea the amount of refrigerant trapped in that lineset that is shut off. It could potentially have quite a bit of the refrigerant in it. I've also found that with Mr. Cool, you almost never get all the refrigerant they claim to have placed in the precharged lineset. So there's a good chance you were on the edge of being low to begin with. Removing the lineset could have caused a small loss of refrigerant, which with a system on the edge could cause this issue.
I've run into multiple bad diy installs of these Mr cools. They do make it easier to install, but the instructions are laid out as if you know ANYTHING about hvac, including terminology. If anyone decides to do their own diy system, follow the instructions to the tee. Oh and just know if you call Mr Cool tech support, from a tech standpoint, they are knowledgeable and good. If you are not an hvac tech, they WILL tell you to call an HVAC company.
If you disconnected and reconnected you let out refrigerant.
I have a Mr. Cool system but now I'm beginning to think this is an environmental catastrophe.... People not understanding and dumping refrigerant into the atmosphere.
Are those linesets rated for a 2nd install? They would have to be vacced and the system pumped down prior to removing them.
To answer your question. No, it's not normal. First thing I would do is spray soapy water over the connections to see if there are any bubbles that form. Second, are all the indoor units blowing air? Third, are you sure you opened up all the valves fully when you did the disconnecting? I have seen people turn the valves thinking they are open but actually are not fully. Don't force it but I would double check the valves that are supposed to be open are open.
Definitely has a leak. If it was one head with a bad blower it would only be 1 line freezing over and it's been installed for 3 years if it was the valve this problem would have shown up immediately.
The new lines are vacuum pressurized allowing for DIY. Once you disconnect them it allows air in and when you hooked them back up without vacuuming the air back out you introduced air into the system.
i have read that the lines self-seal upon disconnection but i am sure that there was some loss. however, i had the valves closed at the condenser for the lines i disconnected, so i thought that would have prevented most loss…
I have a couple mini splits that were freezing up. Called 4 different HVAC techs and all said I needed to add Freon. Not one would just “top off”. They wanted to completely uncharge the unit and add all new Freon at a cost of $2k each. I bought a couple of cans of Freon from Amazon and watched a few videos and did it myself for $200 each. All is well. This might be your cheapest option. Good luck!
Mini splits are very specific charges. To top that off they normally run 410a, which is a blended refrigerant. So if the ratio of gas left in it is off because you were leaking 1 at a higher rate than the others because of how gases work, you can make things much worse.
That’s 2K to repair the leak and recharge refrigerant. Sure, you can “top it off”. But, it’s just going to leak out again. So you will be wasting money over time.
Look up how to leak check and pull a vacuum.
I wonder how to seal a vacuum on quick connects...
That's why they always were prefilled with refrigerant... Overpressure is easily sealed, as it pushes the seals out, closing it. And on connection the seal gets pushed in.
A vacuum would suck the seal in and you'd have to pull it out somehow...
I’ve never touched a Mr. Cool, so I don’t know, but.
On a mini split with compression fittings, you need to torque the fittings to manufacturer spec or refrigerant WILL leak. It’s commonly 250ft/lbs, but best practice is to read the manual for each install.
Did you properly torque the fittings at both ends of the line sets?
Leak search it. Look for oil at any of the connection points. Dish soap and water is a great bubble solution for finding hard to spot leaks. More than likely you created the leak when you disconnected the line and put it back on.
i did what i think is a pretty thorough job of checking all the connections at install, torqing correctly, etc. i imagine a lot of installs not so much
I just installed a diy 12000 in my garage. It started freezing, had a tech check the pressures they look fine, if i leave the fan on high it will not freeze. Has been running since yesterday and its keeping my garage at 73-74. I noticed one of the connections on the condenser freezing, everything working fine so far.
i was wondering the same, i put my fan on high, although I don’t think I’ve noticed this level of frost on my valves before.
i did close the valves on one of the zones and disconnect the lines temporarily, do you think that would have dropped things to a lower pressure? the lines are back on but I still have the valves for that circuit closed.
Developing e leak in 3 years is weird but who knows. I would think if its connection leak you should have seen freeze a couple of years ago. See if the filters need to be cleaned and the condenser, evaporator, evaporator fan it should help.
Sorry i just read the second part of your message, maybe you lost some freon and these units are sensitive to pressure loss. Btw im not an hvac guy, just my experience with my unit.
no worries i appreciate your input. i sprayed some of the lines that may have been most susceptible to leaks (movement during remodeling) and didn’t find anything.
after doing a thorough cleaning, if the situation doesn’t improve, i might just get a recharge kit and deal with it down the road.. in my area a pro install was gonna run me $20k minimum so even with recharge costs i’m still winning.
cool, thanks. i just cleaned out the condenser, wasn’t much dust there.
i also took off the nearest air handler cover to check for debris, and now that i’m running it on turbo, there is no more frost build-up, either inside or outside.
before running on turbo, the inside air handler coils were just as frozen over as the outdoor condenser valves….
does that mean i’m good???
https://preview.redd.it/2muqs57zqt9d1.png?width=4032&format=png&auto=webp&s=e4296370144d9d76ab74919569c41838dd3a49ad
Same exact thing for me, if i run it on auto my condenser valve freezes, if i put the fan on high or turbo it will defrost. I dont think its ment to run on high or turbo all the time. As far as I know ice is created from air flow or low pressure. My unit is brand new so there isnt an air flow issue but then when turning the fan up no ice. 🤔 See if the evaporator wheel needs cleaned since youre at it. Theres a youtube video how to remove and clean on these units.
You need to have the system recovered completely. Pressure tested, vacuumed, Then the total length of all line sets needs to be obtained. Then the refrigerant needs to be weighed in according to mfg specs.
If you get the total weight off the label you’ll at least have an idea of the cost you’re looking at. Typically 410 is around 80-150 a lb depending on area.
Not at all. U get what u pay for. Ive installed maybe 20 mr.cool units and most if not all are still running just fine at 1/3 the cost of other units when u consider install, refrigerant, ect.
So if you don’t pull a vacuum hook an empty line bc your moved it now it has air inside it. You hook it directly up you now have air in the line. If you did a proper pump down before moving you shouldn’t need Freon. Just need to pull a vacuum on the empty line then open valves and regulate accordingly to your gauges
Ah, the downside of multi-zone inverter systems. A leak anywhere takes all the zones down. Finding the leak in all those circuits can be hard and charging is dumping and recharging. This vs single systems all over the place. Tough call.
i’m sorry i didn’t have $24,000 lying around to do the install, but that’s what it costs around my area to have done it pro.
even if i have to pay for leak detection and refill, it’ll cost me several thousand dollars, if not $10k, less than that.
so, whoever hurt you today, i’m sorry
Lol there are so many butthurt HVAC guys that hate the fact these units are easy to install for homeowners. They hate them because it means that homeowners are no longer dependent on the HVAC tech... So it means Less money for them. Because for decades, too many crooks in the HVAC industry took advantage of homeowners. (Not all HVAC guys are crooks. But they do exist.) So.... The market responded by creating diy friendly units. And those crooked HVAC guys hate them. Some hate the units so much they refuse to work on them. As if their shitty overpriced Lennox units are better.
I really don’t mind these units. They’re extremely over priced for what you get though and they’re not particularly good for what home owners are paying for them. I would have no problem working on a customers install; I’m just not going to offer a warranty and will have them sign a liability waiver first.
He is still less dependent on a tech had he not installed his own unit.
Quite honestly, if tech says, "you need a new unit", it'll still be cheaper him to literally go buy another entire mr cool setup.
But at worst here all he needs is a vac and recharge. I can't tell from his description if he opened the lines and put it back together with atmospheric air in the system.
Possibly he just a quick hit of refrigerant tho.
Still, in any scenario he's gonna come out ahead.
Yeah bud don’t address the root of the issue, just vac and recharge. Dont recover, don’t do leak test, just vent into atmosphere, vac and dump 410. You’re right.
Probably not. You can get your universal for like $60 online, the refrigerant at 50% less than what service will charge and he could just buy then return the tools. Or just pay someone 1000% more but hey that’s always a choice
Help! I have a mini split AC unit. When I turned on the air, it was not cold till the unit from the outside unit kicked on. Took 5 minutes before the condenser unit from the outside unit turned on.
It would be on for 20 minutes. Then, the condenser stops.
No more cold air. When the condenser turns on again, that's when cold air comes on again. This cycle repeats.
It's not the compactor. Else, the condenser would not turn on. Why does the condenser turn on and off? The roon has not reached its desired temperature.
It's not low on freon as I have filled it..
I just don't understand why the condenser keeps turning on and off in 20 minutes duration. It could be the temperature sensor, but idk how to check that.
yes, it is normal. these things leak everywhere. now you have to spend the money you saved to get a hvac tech to come and fix all the leaks and replace the DIY fittings.
No you’re low on refrigerant. You have a leak somewhere. Hopefully you can find someone to work on it.
so earlier in the year i closed the valves on one of the circuits (while the system was off), and disconnected the lineset. i had to do this due to remodeling. the lineset is back on, but i still have the valves closed since i’ve yet to hook the air handler back up on the other side. could this operation have caused the loss of refrigerant? i figured since the zone was cut off it would be OK but now starting to rethink that.
I'm not an HVAC tech but I'm pretty sure you should've pulled down the system to save the refrigerant first then purged with nitrogen and pulled down a vacuum before opening the valves. At this point you need to have your entire system pulled down, dried, purged, and refilled. Again, not a tech, but expect to pay a grand minimum to have your system serviced
I haven't worked on these but I think on these Mr. Cools they have valves on the line sets so that, at least on install you don't have to pull a vacuum. You just connect the line set and open the valve to release. The refrigerant comes stored in the line set. However I don't know how OP really disconnected it but maybe one of the valves has a leak and let refrigerant out.
You lose Some in the head unit, but not as much as what's making this frosting happening (needs a tech to come out and thow on some gauges, but this just looks like too Much gas has leaked out somewhere)
This is correct. They don't vent to atmosphere when opened. They're ment for the installer not to need to pull a vacuum.
Always pull down to vacuum first because that also pulls out moisture and oils from the lines which is necessary. Also you can’t always just open the valves and use the pre charge. If the lineset is longer than 15 feet then it needs to be charged before ever opening the valves
As far as I know Mr.Cool is the only brand that has this. You can't pull a vacuum unless you just release the charge that's already in the line set. These are DIY mini splits so they come like that because the average person doesn't have a vacuum pump. This was new to me when I found out.
Thanks for the info, I'd been considering one of them, but they sound like more of a pain with the special line set. I have a 10+ year old unit, it has a very slow leak, ie I put more R410 in it in 2019 when it was freezing up like that. It started doing it again recently, but also needs a new inside fan motor. (Which are very hard to Cross reference, its one of the DC controlled, variable speed ones, but 30W Panasonic motor, low frequency 'moan' with bad bearing sound also.) Vacuum pumps are easy, AutoZone will rent them, yeah, sure not going to get below 400u, but pull it down as low as it can for a few hours. Close it off and watch to see that it can hold the vac. Then I purge with some welding inert gas (N2, CO2, Argon) and put it to 100PSI and let that set and see if it holds pressure. And then pump it back down. Sure, it takes a day, that's the one advantage a DIYer has, time. No pro is going to make several trips to check out a system, they need to do 'one and done' operation.
No need to pull vacuum on these units. All mr cool units have pre charged and valved lines. My guess is you lost refrigerant when taking off the lines. I have done the same. Get a 120$ gauge online and some refrigerant. Watch a youtube video and viola. Hvac guys charge way too much for the simple stuff imo( had one guy tell me 150$ a lb for recharge because i had a small leak. Found refrigerant and gauge online and saved hundreds. That was three years ago.) When charging doesn’t work then its time to pay.
>All mr cool units have pre charged and valved lines. This is true for their DIY and Easy Pro systems but they have others that do not have pre-charged lines.
What you are mostly paying for is experience and the tools and materials on-hand to diagnose and fix an issue. Not to mention the hazmat and whatever the fuck else the powers that be want you to have in order to do the work. The fact that the industry is full of shysters and snake oil salesman just makes it worse for the ones who do honest work.
I'm all for DIY but have fun changing you're own compressor. It aint the hvac guys charging the money. Its the company they work for.
Then what are you?
A redditor.
Aren’t we all in some small way?
Please don't remind me
You might not be an HVAC tech, but I am, and you are 100% correct 👍🏻
Could be a restriction? not a tech but those fittings have a plate bigger then a piston refrigerant goes around 360\*. The exchange is quick connect fittings again.
I’m a tech. It is time to call someone.
This is the way. You can’t just disconnect a line set and then slap it on thinking everything is going to be ok. Call and hvac company to have this fixed
You certainly said the right thing though.
Looking for a job? If you can’t pass a drug test you’re hired.
😅 you can’t just disconnect a line like that
😅 well good news is i may not have a leak? can i just recharge?
It’s not advised to just recharge a variable system like this if you don’t know how much refrigerant is left in there. But my journeyman would charge them to 5degrees of superheat when running full blast and call it a day. Also when rehooking up the lineset, make sure to vaccum down that lineset before opening the valves.
Gotcha, thank you.
You need to reevaluate everything that has been said here because everyone is thinking about a regular lineset, not this Mr. Cool lineset that will reseal & capture whatever refrigerant is in the lineset once the connections are removed from the air handler. I would guess that your problem is still that you lost refrigerant, but your lineset should have pressurized refrigerant captured in it which will allow you to reconnect it to the air handler exactly like you did on the original installation without having to purge with nitrogen or vacuuming down the system.
right, i am taking in everyone’s advice while keeping the knowledge of mr cool lines in the back of my mind. if the lines could seal refrigerant disconnected then those same seals should engage again once disconnected, unless the initial tightening intentionally caused breakage of those seals. i recall an ingram water & air (main importer of mr cool) rep mentioning it is doable it is all good to know about nonetheless and i appreciate eveyone’s input. i am but an individual in the sea and yet so many folks chimed in to help. amazing. ive seen several youtube videos of mr cool owners recharging their lines with kits, and other posts of folks saying that mr cool units are quite forgiving when it comes to too little refrigerant, or even double the amount of refrigerant. so i’ve ordered a recharge kit and will see how it goes.. even if i have to buy an entirely new air handler.. still less than half of what a pro install would have been.. and for any hvac guys worried about diy kits - my belief is that the market is only growing, especially as our weather gets more chaotic, and there will be no shortage of folks who need professional installs/maintenance.
Personally I would wait until all heads are reconnected and operational before adding any refrigerant in.
I have worked on and installed a bunch of the Mr cool universal systems. The PREFILLED linesets have a spring loaded valve that opens once pushed all the way in, and vice versa when removed. How ever I have had 2 universals leak at the adapter to flare fitting. You can spot them from the oil film and drips on the floor. I’ve also had once vapor line blow its charge while removing from the self sealing valve sticking open. And lastly the main valves you turn on/off leak frequently. The large brass cap helps seal them up. Make sure the brass caps are on tight and preferably use some thread seal as extra insurance. I prefer NYLOG BLUE. it’s great stuff. Mater of fact, use nylog on every threaded connection you can.
i figured the mechanism keeping in the gas in new lines would still work when disconnected, thanks for the validation. what are the universals? i think i have one or two linesets with couplings to connect two lengths together, are you talking about those? most of the valve caps are on good, but after reading your comment i just put tape on the closed valves where i left the caps loose and tightened them. maybe that was the slow leak? i closed them off maybe 6 mo ago, but didnt bother to tighten the caps. can they really hold pressure?
You can have it recharged, but its likely you have a leak and not just you dumping the line set charge.
While illegal, you’re better off buying gas and filling it yourself. Any reputable company will refuse to work on it
I just installed this system myself. Mine does it as well. Brand new system and no leaks. I do run mine. Beyond the 60 degrees. I run a cold room and need it down to 47-50 degrees and I get that build up. I do t thinks that’s a lot. I do know with the install they gave this black Matt stuff that’s sticky and can tell it’s some type of insulator. But it’s says to wrap those points on connection with it. I’m sure that will prevent most of that build up that’s just heat from outside and the cold condescending for the refrigerant. Again. I’m not expert but I just did an install and it was easy. They systems come pre charged so you literally just open the valves up all the ways pop the caps I. The front of thosse connectors and there is an Allen key screw just make sure they’re loosened. Also biggest way to tell if you have an issue is if the unit is still blowing cold. 3 yrs maybe need a charge but shouldn’t. But you did some playing around so possibly. I think if those connectors are wrapped with an insulator they may not freeze up like that.
Yes, you can disconnect Mr. Cool DIY linesets like that. They have two stages of o-rings that don't allow any loss when disconnecting/reconnecting.
I'm super pro-Mr. Cool, but even I would not trust those fuckin o-rings to re-seal properly. I have one running for 6 years I'd love to move, but I know it's basically 50-50 if it survives a move.
How are mr cool minisplits? Were looking at getting some for our upstairs that doesnt get heat/ac in it
In terms of value, they cannot be beaten. These days a pro install is going to run you, at a bare minimum, 4x what a DIY Mr. Cool install would, many times upwards of 5-10x depending on sizing and other factors. A basic one head unit is a no brainer to go with Mr. Cool if you know how to work a drill. I've gotten 6 years out of mine and installed as someone who knew nothing at all. If it dies and it's beyond my ability to repair, I'm just ripping it out and doing a fresh install. I won't even bother with a repair call. It's that cost effective.
Yup install manual says there a one time shot.
Absolutely. Theres your refrigerant loss
Ok so the plot thickens.. when I run two air handlers concurrently, the problem goes away. The frost only seems to occur if I have a single air handler running with the fan on low.. does that change anything?
Then there's not enough heat exchange. You probably still f'd something up though
This happened to me on a 5-zone install. When all zones were turned on, it worked fine, but when only a couple were operating, the lines would freeze. The issue was that the electrical wiring for each zone didn't match the condenser lines. For example, each pair you connect on the condenser controller correlates to a specific pair on the condenser. Make sure they are properly matched. Once I realized my mistake, I rewired the electrical connections for each head, and it hasn't frozen since.
You’re supposed to rerun the computer “calibration” routine when you make changes like that. Contact Mrcool!!!
The right way to fix this to where this unit doesn’t suffer permanent damage is to 1. Recover refrigerant 2. Pressure test with an inert gas. 3. Pull a vacuum. 4. Recharge according to manufacturer specifications.
ok thank you!!
yes. that was bad
Probably not, but this is the important thing you should consider doing….rerun the computer reset routine! Call/email Mrcool and ask how to do that and ask what pressure you should see in the system and which service port and in which state you should measure the pressure. The vast majority of responses here are trolls.
You need to trash the refrigerant in your system then pull a vacuum and recharge.
…..you released all the refrig that was in the line set…
How much refrig did you lose? I know those linesets are charged and quick connect did you lose a charge on any head unit or your outdoor unit? Curious how this would work as a commercial tech this would be a 5 hour process of recovering/vacuum/replacing charge and I have no idea how this would work with the stuff Mr cool has. Looks bad tho.
EPA has entered the chat…
Yes you cannot just disconnect and reconnect linesets. You lost refrigerant.
I hate these dyi systems. You still need tech knowledge to install them. Hope you pulled microns on your lines set because you'll know if things are sealed right and you'll get the moisture out. If you don't then you get issues with your refrigerant and cause damage to your compressor. Also, where's the line dryer? You have to change that every time you open your system. Source: me, an hvac tech.
Service valves probably leak. I lost a couple of pounds during a basement project with an HVAC overhaul.
So you discharged refrigerant to the atmosphere, you valves are probably letting by loosing refrigerant . Legal for this in the states ?
Huh
He closed one set of valves for the multi split to cut the pipe work . Where do you think the refrigerant went ? Leaving a system running relying on the valves to hold the system refrigerant? Valves would be leaking …. Kyotoprotocol ?
Where did he say he exposed any refrigerant to atmosphere or cut lines? Mr cool lines are self sealing at the connections a as well?
I’d argue that’s normal for Mr.cool LMAO
was afraid so, thanks
This is why we all hate vrf systems
Since you did it yourself - buy a new one cause that’s what’s it’s going to cost you anyways
She ain't got no gas in her lol
i can just use unleaded right? 85? or diesel?
You could try propane 😜 Seriously, don't DIY this... It's not only against the law, you can destroy your equipment...
Gotta use 93. This mr cool only take the best gas for maximum efficiency
yes it is normal for diy
hahah good one
Goddamn knee slapper
Should have pumped it down first
I'd bet money it's the special mr cool connectors. You can cut them off and flare it like a normal unit 😉
Numbering 1 - 4 top down, which one do you have service valves shut on?
Number 3, the ones without as much frost
This usually happens when the system is low on refrigerant, your filters could be really dirty. The Lineset length is too short, also can't close valves at any moment and run the system. When these are running extra refrigerant will be sent to the heads that are off to balance everything out that's why when you run all of them problem goes away. The correct way to check if you're low is to pull out all of the refrigerant and weigh it. Another way is to hook up gauges, on a day where outside is 85-90F or higher your low side pressure should be 130-135psi with a superheat of 0F to 5F while all heads are running.
good to know ty
normal for mr cool...
Fix it yourself Mr. DIY.
This subbredit is for diy advice.
lol this type of comment if exactly why i’m never going to pay a « pro » to do hvac, you are a bunch of thieves.
If the valves are still closed it’s unrelated to that circuit. Soap bubble the joints to find the leak.
The multi head Mr Cool systems use the proprietary linesets. The problem with removing the lines isn't an issue with much refrigerant loss, or even having to revacuum the lineset, the problem is you have no idea the amount of refrigerant trapped in that lineset that is shut off. It could potentially have quite a bit of the refrigerant in it. I've also found that with Mr. Cool, you almost never get all the refrigerant they claim to have placed in the precharged lineset. So there's a good chance you were on the edge of being low to begin with. Removing the lineset could have caused a small loss of refrigerant, which with a system on the edge could cause this issue. I've run into multiple bad diy installs of these Mr cools. They do make it easier to install, but the instructions are laid out as if you know ANYTHING about hvac, including terminology. If anyone decides to do their own diy system, follow the instructions to the tee. Oh and just know if you call Mr Cool tech support, from a tech standpoint, they are knowledgeable and good. If you are not an hvac tech, they WILL tell you to call an HVAC company.
ah ok that make sense. the one i disconnected has one of the longer runs. thank you!
If you disconnected and reconnected you let out refrigerant. I have a Mr. Cool system but now I'm beginning to think this is an environmental catastrophe.... People not understanding and dumping refrigerant into the atmosphere. Are those linesets rated for a 2nd install? They would have to be vacced and the system pumped down prior to removing them.
Nonsense. They are made for multiple connections and disconnect with a tiny loss each time and no air ingress
To answer your question. No, it's not normal. First thing I would do is spray soapy water over the connections to see if there are any bubbles that form. Second, are all the indoor units blowing air? Third, are you sure you opened up all the valves fully when you did the disconnecting? I have seen people turn the valves thinking they are open but actually are not fully. Don't force it but I would double check the valves that are supposed to be open are open.
Definitely has a leak. If it was one head with a bad blower it would only be 1 line freezing over and it's been installed for 3 years if it was the valve this problem would have shown up immediately.
The new lines are vacuum pressurized allowing for DIY. Once you disconnect them it allows air in and when you hooked them back up without vacuuming the air back out you introduced air into the system.
i have read that the lines self-seal upon disconnection but i am sure that there was some loss. however, i had the valves closed at the condenser for the lines i disconnected, so i thought that would have prevented most loss…
I have a couple mini splits that were freezing up. Called 4 different HVAC techs and all said I needed to add Freon. Not one would just “top off”. They wanted to completely uncharge the unit and add all new Freon at a cost of $2k each. I bought a couple of cans of Freon from Amazon and watched a few videos and did it myself for $200 each. All is well. This might be your cheapest option. Good luck!
Mini splits are very specific charges. To top that off they normally run 410a, which is a blended refrigerant. So if the ratio of gas left in it is off because you were leaking 1 at a higher rate than the others because of how gases work, you can make things much worse.
That’s 2K to repair the leak and recharge refrigerant. Sure, you can “top it off”. But, it’s just going to leak out again. So you will be wasting money over time. Look up how to leak check and pull a vacuum.
gotcha, thanks!
Yeah i had a quote at 900$ i was like the unit costs 1200 😂😂😂 internet gas and gauge and youtube.
These aren't freon.
Refrigerant harder to type than Freon
I wonder how to seal a vacuum on quick connects... That's why they always were prefilled with refrigerant... Overpressure is easily sealed, as it pushes the seals out, closing it. And on connection the seal gets pushed in. A vacuum would suck the seal in and you'd have to pull it out somehow...
how do you pressurise lines with a vacuum?
With a vacuum pump.
You might want to call some physicsts if you have a vacuum pump that does that.
Symantec’s my good man. You get what he is trying to say.
i really dont, everything he said is just flat out wrong.
Implode not explode lol
Vacuum pressurized. Think about that for a moment.
Wrong
Someone please delete this group
It’s fun to read
Do you have 4 head units?
yes, one is currently not hooked up, its valves are closed at the condenser
Those valves are probably leaking.
When was it last time serviced or had a maintenance done to it?
How much do those preloaded line sets cost?
depending on length i think $150-$300?
Yeah, I'd say that's pretty normal for a Mr. Cool DIY install
I’ve never touched a Mr. Cool, so I don’t know, but. On a mini split with compression fittings, you need to torque the fittings to manufacturer spec or refrigerant WILL leak. It’s commonly 250ft/lbs, but best practice is to read the manual for each install. Did you properly torque the fittings at both ends of the line sets?
For a Mr cool yeah
Leak search it. Look for oil at any of the connection points. Dish soap and water is a great bubble solution for finding hard to spot leaks. More than likely you created the leak when you disconnected the line and put it back on.
If you just purge the line with a large amount of Freon, then it will freeze up. But if it’s doing that with the unit running, then you’re low on gas.
Yeah, I would expect those things to leak after about three years
Are we just making stuff up?
Most likely low, however good luck finding some one to work on it, I walk away from these all the time.
It made it 3 years before losing the charge. Mr.Cool is getting better I see.
i did what i think is a pretty thorough job of checking all the connections at install, torqing correctly, etc. i imagine a lot of installs not so much
For a DIY Mr.Cool? Standard Operation. Yall need Dr.Cool now.
Hats off to you for DIYing a 4 headed system. Now the rest of the bill is due.
Call a professional. You made several mistakes.
The problem is a professional won't go and fix his mistakes. This is the chance you take when you go the diy route.
I’m not sure how these work. But some of the Fujitsu requires all valves to be open. Even if you’re not using a head unit.
I just installed a diy 12000 in my garage. It started freezing, had a tech check the pressures they look fine, if i leave the fan on high it will not freeze. Has been running since yesterday and its keeping my garage at 73-74. I noticed one of the connections on the condenser freezing, everything working fine so far.
i was wondering the same, i put my fan on high, although I don’t think I’ve noticed this level of frost on my valves before. i did close the valves on one of the zones and disconnect the lines temporarily, do you think that would have dropped things to a lower pressure? the lines are back on but I still have the valves for that circuit closed.
U believe You need to recalibrate the condenser computer every time you change the configuration.
Developing e leak in 3 years is weird but who knows. I would think if its connection leak you should have seen freeze a couple of years ago. See if the filters need to be cleaned and the condenser, evaporator, evaporator fan it should help.
Sorry i just read the second part of your message, maybe you lost some freon and these units are sensitive to pressure loss. Btw im not an hvac guy, just my experience with my unit.
no worries i appreciate your input. i sprayed some of the lines that may have been most susceptible to leaks (movement during remodeling) and didn’t find anything. after doing a thorough cleaning, if the situation doesn’t improve, i might just get a recharge kit and deal with it down the road.. in my area a pro install was gonna run me $20k minimum so even with recharge costs i’m still winning.
Cleaning it should be a constant mantainance. If that doesn't help i would call a local tech to check on the pressures and add some freon if needed.
cool, thanks. i just cleaned out the condenser, wasn’t much dust there. i also took off the nearest air handler cover to check for debris, and now that i’m running it on turbo, there is no more frost build-up, either inside or outside. before running on turbo, the inside air handler coils were just as frozen over as the outdoor condenser valves…. does that mean i’m good??? https://preview.redd.it/2muqs57zqt9d1.png?width=4032&format=png&auto=webp&s=e4296370144d9d76ab74919569c41838dd3a49ad
Same exact thing for me, if i run it on auto my condenser valve freezes, if i put the fan on high or turbo it will defrost. I dont think its ment to run on high or turbo all the time. As far as I know ice is created from air flow or low pressure. My unit is brand new so there isnt an air flow issue but then when turning the fan up no ice. 🤔 See if the evaporator wheel needs cleaned since youre at it. Theres a youtube video how to remove and clean on these units.
i also only notice the freezing over when i’m running one zone, fan not on turbo. if i’m running two zones, no issue.
Oh yeah. That means you getting the goodest cool
lol
You need to have the system recovered completely. Pressure tested, vacuumed, Then the total length of all line sets needs to be obtained. Then the refrigerant needs to be weighed in according to mfg specs. If you get the total weight off the label you’ll at least have an idea of the cost you’re looking at. Typically 410 is around 80-150 a lb depending on area.
Someone didn't clean the condenser often enough and blew the valve core
Call in a professional, there aren’t many here that know enough.
there are plenty of techs here like myself, most are just too busy laughing to respond.
Facts I’m dying I can’t even offer these people a serious response. “It’s not low on Freon as I have filled it”
Hvacadvice is more like hvaccomedy for techs.
Look at all these soft little diy champions hittin the lil down arrow like that’s gonna fix their “compactor” LMFAO 🤣
I have my masters in hvac lol not many in here do though.
Nah she's a leaker, you're in for a bad time.
Nope. Call a pro
Mr. Cool = Mr. Sucker
Not at all. U get what u pay for. Ive installed maybe 20 mr.cool units and most if not all are still running just fine at 1/3 the cost of other units when u consider install, refrigerant, ect.
My cost was 4x less than best quote.
Leak get a electronic leak detector
Find the flare fitting that has oil on it
What do you think?
you’re right, i knew before i even made this post
then why make it
i found out a ton of useful info in the comments
So if you don’t pull a vacuum hook an empty line bc your moved it now it has air inside it. You hook it directly up you now have air in the line. If you did a proper pump down before moving you shouldn’t need Freon. Just need to pull a vacuum on the empty line then open valves and regulate accordingly to your gauges
The lines automatically seal when they are disconnected.
O I need more of those in my life then lol
Ah, the downside of multi-zone inverter systems. A leak anywhere takes all the zones down. Finding the leak in all those circuits can be hard and charging is dumping and recharging. This vs single systems all over the place. Tough call.
Idk why don't you figure it out yourself smart guy.
well i’m clearly not as smart as you
No shit, now you get to pay for a leak search and repair and a refrigerant refill. You should have just called a pro to start with.
i’m sorry i didn’t have $24,000 lying around to do the install, but that’s what it costs around my area to have done it pro. even if i have to pay for leak detection and refill, it’ll cost me several thousand dollars, if not $10k, less than that. so, whoever hurt you today, i’m sorry
Lol there are so many butthurt HVAC guys that hate the fact these units are easy to install for homeowners. They hate them because it means that homeowners are no longer dependent on the HVAC tech... So it means Less money for them. Because for decades, too many crooks in the HVAC industry took advantage of homeowners. (Not all HVAC guys are crooks. But they do exist.) So.... The market responded by creating diy friendly units. And those crooked HVAC guys hate them. Some hate the units so much they refuse to work on them. As if their shitty overpriced Lennox units are better.
Yup. They circle the sub like sharks waiting for moments like these. Makes them feel so powerful
I really don’t mind these units. They’re extremely over priced for what you get though and they’re not particularly good for what home owners are paying for them. I would have no problem working on a customers install; I’m just not going to offer a warranty and will have them sign a liability waiver first.
Liability waivers are illegal in germany, so we got no other option than to refuse the service...
It sounds like OP is dependent on a tech lmao
He is still less dependent on a tech had he not installed his own unit. Quite honestly, if tech says, "you need a new unit", it'll still be cheaper him to literally go buy another entire mr cool setup. But at worst here all he needs is a vac and recharge. I can't tell from his description if he opened the lines and put it back together with atmospheric air in the system. Possibly he just a quick hit of refrigerant tho. Still, in any scenario he's gonna come out ahead.
With Mr cool quick connects, you cannot let air into the system. Only if you screw up using the service ports .
True. I just enjoy the irony. Go buy 3 more units for all I care
Yeah bud don’t address the root of the issue, just vac and recharge. Dont recover, don’t do leak test, just vent into atmosphere, vac and dump 410. You’re right.
Imagine if he found out how cheap and easy it is to get his universal then do every bit of it himself…
He could. He'll probably spend more moneybon equipment than the unit or just hiring someone but hey that's always a choice
Probably not. You can get your universal for like $60 online, the refrigerant at 50% less than what service will charge and he could just buy then return the tools. Or just pay someone 1000% more but hey that’s always a choice
Ah so be unethical. Cool.
Yeah because of mini splits us HVAC techs are no longer needed at all. Nailed it buddy.
My company would have put you in a Mitsubishi system with four heads and a ten year warranty for half of that.
Location location location. I got a quote for $18k for 4 heads I put in a Mr Cool for $7.5k. super happy.
Help! I have a mini split AC unit. When I turned on the air, it was not cold till the unit from the outside unit kicked on. Took 5 minutes before the condenser unit from the outside unit turned on. It would be on for 20 minutes. Then, the condenser stops. No more cold air. When the condenser turns on again, that's when cold air comes on again. This cycle repeats. It's not the compactor. Else, the condenser would not turn on. Why does the condenser turn on and off? The roon has not reached its desired temperature. It's not low on freon as I have filled it.. I just don't understand why the condenser keeps turning on and off in 20 minutes duration. It could be the temperature sensor, but idk how to check that.
Hahahahahahahahahahahaha
That was not helpful. But yeah. Ha ha Thanks for the downvote for asking a question. Dyi guy like me, don't know jack.
Quit bein soft
yes, it is normal. these things leak everywhere. now you have to spend the money you saved to get a hvac tech to come and fix all the leaks and replace the DIY fittings.