My House Air Cond Took a Dump - Tech was Stumped

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Rheem gas furnace and central A/C, 2004 manufacture date, installed 2005 new construction house, put into service (started using) 2006 when we bought the place. I don't know the tonnage but house is typical 1.5 story 2250 sq ft, brick 1st story, siding for the upper 1/2 story. Dual zone by diverter in the supply plenum.

So the unit has been virtually trouble free and serviced every other year with me changing filters approx every 9 months (20x25x5 Honeywell). Has some kind of anti-bacterial ultravoilet light bulb thingy installed in the return plenum not sure what it's called, supposed to help against [censored] in your air I guess.

Anyhow, had the recent heat and humidity wave last week and week before, highs mid 90's high humidity w/ heat index (how hot it feels) in the 100-105 range. The unit did fine. Thermostat @ 77 lower zone 79 upper (no one upstairs anymore) during day, down to 74/79 evenings and overnight. Unit pulled the temp on lower zone to 74 without much trouble or excessive running through the heat wave.

But, over this past weekend, after a front came in and heat wave gone, temps more mild, the unit inexplicably took a dump and stopped cooling well, would run and run struggling to bring lower zone to 75 and wouldn't get it any lower. Air out of registers barely cool. And the kicker: when the unit was running I could hear the refrigerant in the lines where they enter the evap coil air handler box making the sounds they would normally only make at shut down when pressure is equalizing-- gurgling sound. To me, and I know only enough about HVAC to screw something up, that hinted at a low charge i.e. a leak. Next door neighbor changed cable providers and they marked underground lines recently in between our houses and my first thought was maybe they tripped and fell into my condensor unit and triggered a leak. But it looked undisturbed.

Called out the HVAC contractor. Now for the kicker: He used his electronic sniffer and had a time finding any significant leaks !! Said he got some really weak indications in the air handler at the evap coil, but found the unit real low on charge. forget the figures he said but said it was only producing a 10 degree drop on the coil it was so low. Charged it to get me going, but the bad news is the unit uses R22 and the materials charge alone for the amount he had to put in was $238. The invoice looks like it says R100 though, but he did say it was labeled for R22.

So it's cooling like a champ now (shouldn't have said that probably...) but we were both scratching our heads on how it could lose that much Freon in that short time span and not be indicating a larger leak somewhere.

Anyhow, he said the evap coil was clean but did show a level of corrosion expected on a unit in service almost 12 yrs. Said should consider just replacing the entire system since install of a new evap coil and the necessary capture of existing refrigerant plus the cost to recharge the entire system with the old stuff might represent sinking too much expense into an old system. Said he'd have their estimator give me a call.

I'll probably collect several estimates.

I do plan to sell the place soon, next year or so, so I suppose a new furnace and air cond system might help it on the market.

But [removed] anyhow...
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It depends on the cost of a new system.

I had a guy tell me the same thing when my R22 system had a leak and he offered a Heil (2nd tier) 4 ton unit as a replacement for $6600 installed. Reuse my air handler and lines and only replace the condenser and evaporator.

Sent him packing and found a place that would install a Carrier base unit for $3700.

A little secret about R22 vs R410. 410 runs at higher pressure so the evaporators have thicker walls to hold the pressure. You CAN run a 410 evaporator with R22 but you need to change either the TXV (if it has one) or the orifice tube to R22 specifications.

look at https://www.acwholesalers.com for prices for the basic parts. Question any outrageous markups.
 
I just bought a place with two new Trane units. One for each floor. I am glad they are new but in making a offer on the house I did not factor in new HVAC not a new septic.
 
I got a hybrid system last year and went middle of the road because all of the units are good for 10 years these days. I will however never get a hybrid system again. No problems but they are about useless here in the east. I run my system now as a dedicated AC unit and an oil heater. I dialed out the hybrid mode.
 
i probably have the same system at my house. a few years ago i lost my charge slowly over the winter. when i started it up i heard a hissing in the line outside. there was very very small pinhole in the line close to the outsdie umit. had a guy come and braze the hole and recharge the system. Cost me $200 and its been running well since.

Check the lines between the compressor and evap
 
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Mine had trouble in June cooling the house, called out an A/C guy and he took a picture of the evaporator and showed me, 2 oily leaky spots.

He said it's probably just a slow leak and he'll recharge it and it should be fine for another year or two. Still running like a champ.

I guess if it's still cooling, that's good.
 
You won't get 100% of your money back putting in new AC if you're dumping your house. "AC works", yes.
 
He should have put some refrigerant dye in it-that way, the next time it runs low, it'll be obvious where the leak is. Evaporators (usually A-coils) do get leaky with age, though.
 
Also, I would get a second opinion (unless you REALLY know the service tech & company well)-very many companies pay bonuses to their techs for selling new systems, and 12 years really isn't that old for an A/C system. Mine is now 20 years old, and other than a mechanical compressor failure & a couple of contactors & run capacitors, it's still chugging along just fine, although the condensing unit isn't going to win many beauty contests.
 
Be careful when ordering a new system. Make sure that the delivery is to your door. With many of these new units the shipping company will contact you saying the truck won't be able to make it to your house. You then have to pick it up on the side of the highway while cars are whizzing by.
 
Originally Posted By: SatinSilver
Be careful when ordering a new system. Make sure that the delivery is to your door. With many of these new units the shipping company will contact you saying the truck won't be able to make it to your house. You then have to pick it up on the side of the highway while cars are whizzing by.


There truly is one in every crowd . . .
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Originally Posted By: PimTac
The cynical side of me is thinking that someone stole your refrigerant. It happens.


I was going to write the same.
 
Originally Posted By: PimTac
The cynical side of me is thinking that someone stole your refrigerant. It happens.


Hummmm . . .

Maybe I'll put some tamper-evident tape across the access panel.
 
Originally Posted By: Leo99
Originally Posted By: PimTac
The cynical side of me is thinking that someone stole your refrigerant. It happens.


I was going to write the same.


Just googled it. Freakin' huffers huh? It would explain the sudden drop in cooling ability in light of the tech scratching his head about only finding trace hints of r22 with his sniffer, around the evap coil. But who knows.

Whatever the case, just came back inside from placing a few clandestine strips of scotch magic transparent tape few places where access panel mates up to rest of frame. Happens again and the tape is disturbed then will know what's up.
 
Stealing refrigerant is unlikely, you need a recovery machine to suck it out and store it in another container. New installations require you to install what are called "locking caps", you need a special tool to remove the caps that go on the service ports. Leak detectors can't really detect small leaks, dye is the only solution.
A friend of mine has a small leak in his r22 system, I charge it up once a year with r407 and it last one year,until he decides to replace it with r410.
 
Mine is older than that and a Rheem Heat pump, but my guy says they almost always leak at the inside coil. He charged it with a sealer and said he’d come check it in 3 weeks or so and we could go from there.
 
I live in Southern California. My unit is 17 years old. It's a Rheem 2.5 ton unit. It's never been touched except for servicing the electrostatic and furnace filters when needed. It works great and actually, I'm afraid to have it touched by someone that might do more damage than good.

Should I be getting prepared to purchase a new unit? Do the improved new units make that much difference in operating costs that fixing an old unit is a waste of money?
 
Finding a good HVAC tech is the key. I recently had a thread about my daughter's 1.5 yr old heat pump/AC quitting in the middle of a heat wave. The 4th tech finally found a leak where a small copper tube was soldered into a larger copper tube near the compressor. He squirted everything with his soapy water squirter and there it was. Soldered it up, charged it up and so far so good a week later. He told me with all the unsupported tubes and touching tubes wiggling and vibrating while the unit is running they spend a lot of time finding & fixing leaks.
 
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