Residential Air Handler help (freezing)

dcg9381 · May 5, 2026

danski0224 said:
The unit is cooling as it hypothetically freezes up. Usually, airflow will significantly reduce or stop when the coil freezes.

Yea, I think that was his point that the HVAC is hold temp here (it's not hot yet). I didn't stick my head in there and verify ice on the coil, which I should have done. I assumed that if it was dripping that it was frozen. That's my fault as a consumer. Let me give it some run-time.

danski0224 said:
Uh huh... [compressor type is loud]

You're calling BS? I'm a clueless consumer on this stuff... But made some sense to me why it was "loud" (only for a second at start up) during hot temps....

I sorta get what he was saying on the drain side, because it was uncapped upstream of the p-trip I assumed it was on the negative pressure side, which passed my "smell test".

They've got a solid reputation... If they were wrong and the coil is freezing or internal pan is shot, I'll push back on the first service call.

I wish I had the time required to work in [every trade] for a year....

American Locomotive · May 5, 2026

Copeland Scrolls *can* sound absolutely terrible on start up.

BurtEggley · May 5, 2026

American Locomotive said:
Copeland Scrolls *can* sound absolutely terrible on start up.

or shutdown. The internal valve on our old one went bad around 2018. It would shake the house like a fog horn being nearby. We replaced the compressor and all was well again. We could have added an external valve but the compressor was already 15 years old at that point. New one was so quiet when it ran.

I also have no idea what the "smell test" has to do with a coil freezing. Maybe there was a smell and the solution was to fix the drain. If someone is using a big thick air filter, which limits return air, I can visualize the suction of air coming in thru the drain pipe stopping the water from draining when it is on, and making a stink. In that case the lack of air flow because of the blocked filter might cause the coil to freeze due to lack of air flow. There will be other more expensive problems in the future if that is what has been going on. And the electrical bill would be a lot higher than it needs to be too.

dcg9381 · May 6, 2026

American Locomotive said:
Copeland Scrolls *can* sound absolutely terrible on start up.

Thanks.. A little confirmation goes a long way. Had I know that, I wouldn't have allowed this unit to be installed. I engineered out some other common builder mistakes like high-velocity return grates, but you learn something every time...

BurtEggley said:
I also have no idea what the "smell test" has to do with a coil freezing. Maybe there was a smell and the solution was to fix the drain. If someone is using a big thick air filter, which limits return air, I can visualize the suction of air coming in thru the drain pipe stopping the water from draining when it is on, and making a stink. In that case the lack of air flow because of the blocked filter might cause the coil to freeze due to lack of air flow. There will be other more expensive problems in the future if that is what has been going on. And the electrical bill would be a lot higher than it needs to be too.

Smell test = "makes reasonable sense and isn't complete BS"

I made the assumption that the air handler was frozen because the whole handler was leaking opposite end of the drain. Frankly, that was an ASSumption I felt safe to make, but I didn't verify it despite it being easy enough to do.

Let me run this thing for a few more days with the cap on the high side of the trap...

Honestly, I feel really stupid about this. It almost certainly was capped when installed, but I've been up there messing with it (about to install a chlorine tablet feed in the drain line) and left the cap off. I had no idea that simple mistake could cause this.

danski0224 · May 6, 2026

dcg9381 said:
I had no idea that simple mistake could cause this.

That's because it couldn't drain like it is supposed to, due to the condensate pipe seeing negative pressure because of the cap being left off.

BurtEggley · May 6, 2026

Ok so the problem was always drainage. The "freezing" was a guess of the cause and not an actual symptom. The repair makes sense now. If the unit is in a place where some water from the hose running thru it won't drip onto a floor or ceiling, flush it out good with a hose if the tech did not do that. Otherwise use compressed air, or a wet vac sucking on the line outside where it drains out. Make sure that line is fully open and cleaned out. We came home one time years ago in a townhome we lived in back then, and found an inch of water on the floor near the HVAC system. The dogs had buried the outlet line to stop water from messing the area where they liked to lay down in the shade.

dcg9381 · May 7, 2026

BurtEggley said:
flush it out good with a hose if the tech did not do that.

Actually he did. It was unnecessary (I'm capable of maintaining the drain), but he ran some sort of chemical that "you need a license to have" through and made sure it came out. All good.

BurtEggley said:
Otherwise use compressed air, or a wet vac sucking on the line outside where it drains out. Make sure that line is fully open and cleaned out.

I get it, I've had to ****/blow/acid that thing out before. Installing a chlorine feed so I don't have to worry about it as much. Cheaper than HVAC "tablets".

dcg9381 · May 14, 2026

Yea, well, the old "cap the drain" trick didn't pan out. Definitely freezing up... It's a bit odd, because this thing can run for weeks and is fine, so I assume it's a problem that's going to get worse.

danski0224 · May 14, 2026

The cap wouldn't have much of anything to do with freezing. Just not draining properly.

The coil freezing is another problem.

Ohmthis · May 14, 2026

dcg9381 said:
Yea, well, the old "cap the drain" trick didn't pan out. Definitely freezing up... It's a bit odd, because this thing can run for weeks and is fine, so I assume it's a problem that's going to get worse.

Back to the drawing board.

fitter30 · May 14, 2026

Time for a qualified service person. Freezing isn't always air flow or dirty xoil/ blower wheel. A distributor tube or orfice metering device an be clogged on a expansion valve coil. Cap tube coil could have a feeder tube clogged. Leaking water dripping off the coil instead of running down the face. Spray bottle with dish soap and warm water to break the surface tension.

fitter30 · May 14, 2026

Time for a qualified service person. Freezing isn't always air flow or dirty xoil/ blower wheel. A distributor tube or orfice metering device can be clogged on a expansion valve coil. Cap tube coil could have a feeder tube clogged. Leaking water off coil instead of running down the face. Spray bottle with

dcg9381 · May 15, 2026

OK, I'm sure this has been discussed before. This a Rheem unit, about 4 years old, with a 10 year warranty. It's R-410A, which is no longer made.
I asked the tech if he'd dye it, as I "assume" that most leaks happen at the flares. He said that wasn't true and most leaks happen at the evaporator, so didn't want to dye it.. I asked about "warranty" - said they won't warranty Rheem and it doesn't matter anyway as R410 units cannot be legally replaced. He want to replace everything with Trane, probably $10k+. Short term, refill at $140/lb or so...

I can talk to a Rheem dealer, but what's the deal on failing 410A units? As they are "in service" currently, I would assume they could be replaced, but dunno that this is true... Warranty is parts only... Original installer does "new install only" so that's probably a dead end. Advice?
RHEEM HEAT PUMP SYSTEM 2021
MODEL RP1436AJ1NA

danski0224 · May 15, 2026

This is the part where warranties are worthless.

Probably need to start at the Rheem website and find local dealers. Then you need to call them and ask about diagnostics and repairs or replacement on your equipment.

Generally speaking, a contractor doesn't want to warranty stuff installed by others. It really is a pain in the ***. My supplier won't provide warranty parts out of inventory- it has to be shipped from the manufacturer.

I'm sure that an evaporator coil could be found, if that's the problem.

And there's the other issue. Are there concealed joints in the lineset?

The leak needs to be found, and unless the lineset is being replaced, it needs to be pressure tested.

Customers don't want to pay for diagnostics, but they'll damn sure call later when the refrigerant leaks out again and demand free warranty work - and it's not leaking at the new equipment.

And yes, the other elephant in the room is finding someone capable of performing the diagnostics.

The two guesses are: a refrigerant leak or an "inefficient compressor", which can't be diagnosed without gauges and subcooling/superheat.

But finding someone to warranty your stuff will be the first obstacle.

PoorUB · May 15, 2026

dcg9381 said:
OK, I'm sure this has been discussed before. This a Rheem unit, about 4 years old, with a 10 year warranty. It's R-410A, which is no longer made.
I asked the tech if he'd dye it, as I "assume" that most leaks happen at the flares. He said that wasn't true and most leaks happen at the evaporator, so didn't want to dye it.. I asked about "warranty" - said they won't warranty Rheem and it doesn't matter anyway as R410 units cannot be legally replaced. He want to replace everything with Trane, probably $10k+. Short term, refill at $140/lb or so...

I can talk to a Rheem dealer, but what's the deal on failing 410A units? As they are "in service" currently, I would assume they could be replaced, but dunno that this is true... Warranty is parts only... Original installer does "new install only" so that's probably a dead end. Advice?
RHEEM HEAT PUMP SYSTEM 2021
MODEL RP1436AJ1NA

Find a HVAC tech that actually is willing to repair something. You can still buy R410 coils. You can still buy R410. Rheem should have a replacement coil for that unit, if not and aftermarket coil can be made to fit, the tech just needs a bit of creativity, and just a little bit.

Factory warranty will do something, even it the parts are not available, they will compensate you some how. although anyone other than a Rheem dealer might not be able to get it warrantied. Any HVAC company should be able to get the Rheem coil, if that is what is wrong.

The tech you had look at it just wants to sell new equipment. The standard HVAC contractor model of doing business today. I would be ashamed to operate like these guys. Replace a four year old system, ridiculous!

You need someone to take the time to recover the refrigerant, pressure test the system and find the leak, if that is what is wrong with it. We don't even have a clue at this time. A couple hours should be enough to find a leak, and more for the actual repair. When I was a tech I never had a leak I couldn't find in about an hour, unless the line set was buried and leaking.

dcg9381 · May 15, 2026

PoorUB said:
Find a HVAC tech that actually is willing to repair something. You can still buy R410 coils. You can still buy R410. Rheem should have a replacement coil for that unit, if not and aftermarket coil can be made to fit, the tech just needs a bit of creativity, and just a little bit.

So I can find a Rheem dealer, I assume they'd be a contractor that would do a Rheem repair. The coil appears to be $1000 - so that's what I'd save. I assume this is a 6-10 hour job at $1-$2k, assuming the leak is at the evaporator coil (yes, more debug time to find that for sure). Seems like this would be a better option than dropping another $10k into a new system.

Appreciate the help here, not my wheel house.

PoorUB · May 15, 2026

dcg9381 said:
So I can find a Rheem dealer, I assume they'd be a contractor that would do a Rheem repair. The coil appears to be $1000 - so that's what I'd save. I assume this is a 6-10 hour job at $1-$2k, assuming the leak is at the evaporator coil (yes, more debug time to find that for sure). Seems like this would be a better option than dropping another $10k into a new system.

Appreciate the help here, not my wheel house.

Sounds reasonable to me.

For me, if I was doing the job, I would expect maybe 2 hours diagnostics, find the leak or what ever else is wrong, and 4-5 hours to replace the coil. Maybe more, but less than 10 hours total. Even if you had to buy a coil at $1,000, $2,500 or so seems like a better deal than $10,000! Depending on the outdoor unit I might be able to do the coil change out in 2-3 hours.

The next tech might find something else wrong, dirty blower wheel perhaps, then the diagnostic time and another 1- 1 1/2 hours to do a proper blower cleaning.

BurtEggley · Saturday at 2:28 PM

Until the leak is found, there is no way to know what will fix it. It can be anywhere, and even something as simple as a bad schraeder valve core.

BurtEggley · Saturday at 2:43 PM

Don't know these people, Summit Air Conditioning & Heating in Austin, but a review of their Yelp and Google reviews is quite encouraging. 459 Google reviews and no complaints. Might consider a second opinion from them. 4 year old HVAC should be under warranty as long as you meet the manufacturer warranty requirements. Example, we have a Carrier. It is also a 10 year warranty but I had to register it to get that.

American Locomotive · Saturday at 11:16 PM

dcg9381 said:
OK, I'm sure this has been discussed before. This a Rheem unit, about 4 years old, with a 10 year warranty. It's R-410A, which is no longer made.
I asked the tech if he'd dye it, as I "assume" that most leaks happen at the flares. He said that wasn't true and most leaks happen at the evaporator, so didn't want to dye it.. I asked about "warranty" - said they won't warranty Rheem and it doesn't matter anyway as R410 units cannot be legally replaced. He want to replace everything with Trane, probably $10k+. Short term, refill at $140/lb or so...

I can talk to a Rheem dealer, but what's the deal on failing 410A units? As they are "in service" currently, I would assume they could be replaced, but dunno that this is true... Warranty is parts only... Original installer does "new install only" so that's probably a dead end. Advice?
RHEEM HEAT PUMP SYSTEM 2021
MODEL RP1436AJ1NA

R410a is still being made, and components for r410a systems are still being manufactured, and you're still allowed to service and repair r410a systems. Odds are your HVAC company was purchased by a major national/regional chain, and is now only interested in doing new installs.

Find a smaller or independent guy. Or buy a refrigerant gas detector and find the leak yourself.

dcg9381 · Monday at 9:48 AM

American Locomotive said:
Odds are your HVAC company was purchased by a major national/regional chain, and is now only interested in doing new installs.

Nah, they were always "new install only" shop for home builders. I will ping them though. I would think that as part of "licensed [brand] dealer" you should have to repair.. But there are ways around that.

American Locomotive said:
Find a smaller or independent guy. Or buy a refrigerant gas detector and find the leak yourself.

Do you not use dye on these systems like automotive?
I'd need to purchase a means to recover the existing gas, which ain't cheap. I think the "license" for refrigerant is pretty easy to accomplish in Texas... Assuming it IS the evaporator coil, do you just replace the coil or the entire air handler?

PoorUB · Monday at 10:28 AM

dcg9381 said:
Nah, they were always "new install only" shop for home builders. I will ping them though. I would think that as part of "licensed [brand] dealer" you should have to repair.. But there are ways around that.

Do you not use dye on these systems like automotive?
I'd need to purchase a means to recover the existing gas, which ain't cheap. I think the "license" for refrigerant is pretty easy to accomplish in Texas... Assuming it IS the evaporator coil, do you just replace the coil or the entire air handler?

I have had zero luck with dye, but pressurizing the system with nitrogen and a little R410 for the sniffer to pick up and I always find the leak.
You can replace just the coil.

Ohmthis · Monday at 2:56 PM

dcg9381 said:
Nah, they were always "new install only" shop for home builders. I will ping them though. I would think that as part of "licensed [brand] dealer" you should have to repair.. But there are ways around that.

Do you not use dye on these systems like automotive?
I'd need to purchase a means to recover the existing gas, which ain't cheap. I think the "license" for refrigerant is pretty easy to accomplish in Texas... Assuming it IS the evaporator coil, do you just replace the coil or the entire air handler?

I do not like using dye unless everything else has failed to find anything. Dye makes a mess, is only mildly effective, and gets in all of your refrigerant tools (I use an old set dedicated for dye. That’s whether I used the dye or someone else). I agree that pressure, sniffer, and bubbles are my go to’s.

PoorUB · Monday at 5:50 PM

Ohmthis said:
I do not like using dye unless everything else has failed to find anything. Dye makes a mess, is only mildly effective, and gets in all of your refrigerant tools (I use an old set dedicated for dye. That’s whether I used the dye or someone else). I agree that pressure, sniffer, and bubbles are my go to’s.

We had a residential AC that leaked like a sieve and no one could find the leak. I found out between a couple techs that had dropped enough dye in it for a 15 ton system and couldn't find the leak. I got to manage the service department about that time and I sent the new kid over with instructions to not go home until he found the leak. I told him to recover the refrigerant, cut off the line set and pressure test the condenser, then cap the line set and pressure test it. The line set connected to the a-coil was leaking somewhere. I told him to cut the line set off the A-coil and pressure test the line set again, then pressure test the the a-coil separately The A-coil leaked like a sieve. He said he could watch the pressure gauge drop slowly. This whole operation took him a bit over an hour. We had untold hours from the other techs trying to find the leaks that we never charged for as it was a good customer. He replaced the A-coil and brought the leaker back to the shop. We took it into a dark room with a UV light and not a trace of dye on it.
When I quick leak check didn't find anything this got to be our standard procedure to find a leak. Cut the system into sections and pressure test the individual sections. We always found the leak! We quoted customers that within two hours we would find it when others had failed. It was kind of an excessive way to do it, but you can screw around for hours, or just dive in and get it over with.

dcg9381 · Monday at 6:07 PM

PoorUB said:
Cut the system into sections and pressure test the individual sections. We always found the leak! We quoted customers that within two hours we would find it when others had failed. It was kind of an excessive way to do it, but you can screw around for hours, or just dive in and get it over with.

Thanks. As I understand it, this isn't like mini-splits. No flares (at least not at the compressor) and everything is soldered. You guys "cut" the system into sections, I assume compressor, mid-lines, evaporator and then leak tested? Makes sense to me....

The kicker here is the 410 system. Best case it's a "part failure" that's warranted and I can't imagine a part that's more than $1k (wholesale). Labor isn't warrantied. Standard consumer dilemma. Assuming I wanted to go through the learning curve, the tools to capture R410 are pretty expensive. Not $10k expensive, which is I'm sure what I'll get bent over for on a new system... but my "free" time is at a premium right now and learning curves don't appeal...

Sounds like the right diagnostic would be to pull the existing R410, pressurize it up with nitrogen and find the leak. Best case, that's a part failure that's under warranty.

mm08822 · Monday at 6:36 PM

dcg9381 said:
Thanks. As I understand it, this isn't like mini-splits. No flares (at least not at the compressor) and everything is soldered. You guys "cut" the system into sections, I assume compressor, mid-lines, evaporator and then leak tested? Makes sense to me....

The kicker here is the 410 system. Best case it's a "part failure" that's warranted and I can't imagine a part that's more than $1k (wholesale). Labor isn't warrantied. Standard consumer dilemma. Assuming I wanted to go through the learning curve, the tools to capture R410 are pretty expensive. Not $10k expensive, which is I'm sure what I'll get bent over for on a new system... but my "free" time is at a premium right now and learning curves don't appeal...

Sounds like the right diagnostic would be to pull the existing R410, pressurize it up with nitrogen and find the leak. Best case, that's a part failure that's under warranty.

I would think you could ask for prices to recover the 410A, pressurize w/N2, then evacuate the fixed system, and re-charge with the recovered 410A plus topping off. Obviously the wildcard is the in between of chasing/finding/repairing the leak. No one knows what will be the cause so no sense to ask for a guess in that area.
This would at least give you an estimate of the same defined procedures from different companies that would be required if you were to chase the leak. (well, for those that may respond.)

Snapped-off · Monday at 6:37 PM

I replaced my A-coil 2 years ago. I think it was $450 - $500.

duneslider · Tuesday at 12:12 PM

I had a similar issue a handful of years ago, I think it may have been Carrier, and the tech used his sniffer to find the leak (on the coil on the outdoor unit). Carrier said for warranty they had to try to solder the pin hole first before replacing. The guy did the repair, looked more like brazing to me but still it was repaired and was still working fine 8 years later when we moved. I think finding a tech that isn't just motivated to sell equipment is the best bet. In my case, my unit was newish and they had to warranty it. The original guy that came out wasn't qualified/capable of doing diagnostics and repair, so they sent out a more experienced tech to take care of it and he did a great job. The first guy that came out just hooked up gauges and said "yep, its low I will fill and you will be good." I pushed back and said there must be a leak and I want it fixed right and not just refilled.

danski0224 · Tuesday at 12:12 PM

If the system is leaking, the reclaimed 410A should not be used.

TRWham · Tuesday at 1:54 PM

American Locomotive said:
Copeland Scrolls *can* sound absolutely terrible on start up.

A Compliant Scroll starts unloaded so it can rattle a bit. It has to get up to speed to generate enough force to hold the flanks in radial contact and enough pressure to hold the tips of the orbiting scroll to the fixed scroll axially.

dcg9381 · Tuesday at 2:00 PM

danski0224 said:
If the system is leaking, the reclaimed 410A should not be used.

And it keeps getting better..

Seriously though, I appreciate all the help here. Not my wheelhouse.

danski0224 · Tuesday at 2:56 PM

It's because 410A is a blend, and the parts don't leak out equally.

Ohmthis · Tuesday at 7:39 PM

Snapped-off said:
I replaced my A-coil 2 years ago. I think it was $450 - $500.

Prices have shot up dramatically. I quoted a job in September of 2025. I requoted the same exact equipment in January 2026. The difference was over $3500. I was floored!

Snapped-off · Tuesday at 7:39 PM

dcg9381 said:
And it keeps getting better..

Seriously though, I appreciate all the help here. Not my wheelhouse.

Fun fact since we're learning.

A lower case letter after the refrigerant indicates it's an isomer, or single gas - like R-134a.

Upper case indicates a blend of multiple gases - like R-410A, as Danski mentioned.

Snapped-off · Tuesday at 7:40 PM

Ohmthis said:
Prices have shot up dramatically. I quoted a job in September of 2025. I requoted the same exact equipment in January 2026. The difference was over $3500. I was floored!

Hot dog. I'll have to see if I saved the receipt to see what brand mine was. It was a 3.5T Armstrong replacement. Wasn't OE though.

danski0224 · Tuesday at 7:49 PM

Ohmthis said:
Prices have shot up dramatically.

That's an understatement.

There have been plenty of manufacturing changes, so a direct comparison isn't really possible, but I wouldn't be too far out of line to say that the prices have nearly doubled when compared to the before times.

It doesn't get any less expensive to wait.

Residential Air Handler help (freezing)

Well-known member

Well-known member

Well-known member

Well-known member

Well-known member

Well-known member

Well-known member

Well-known member

Well-known member

Well-known member

Well-known member

Well-known member

Well-known member

Well-known member

Well-known member

Well-known member

Well-known member

Well-known member

Well-known member

Well-known member

Well-known member

Well-known member

Well-known member

Well-known member

Well-known member

Well-known member

Well-known member

Well-known member

Well-known member

Well-known member

Well-known member

Well-known member

Well-known member

Well-known member

Well-known member

Well-known member