My home AC blows warm air.

[sharkmonkey]

Anybody want to take a shot at helping me troubleshoot my Air Conditioner? It's not for my car but for my house.

It worked fine last summer. We even turned it on once over the winter when we had a house full of guests. It blew room temperature air then too. I'm not sure what any of the parts are called but I'll do my best.

There is a pipe that goes into my house. It's frozen (see pic). Inside the house, the ice melts and drips in the basement. There is a return line that goes back out to the AC unit. It is room temperature. The radiator things are room temperature as well.

There is a drain pipe that usually drips water but it hasn't been. I thought maybe it was plugged. I put a vacuum hose on it and sucked some water out.

What can I check for?
Here's the pic.
http://i69.photobucket.com/albums/i72/thesharkmonkey/other/attachment.jpg

[RG67BEAST]

Wait until it gets hot outside. Otherwise the compressor won't work.
Ray

[sharkmonkey]

It's almost 70 degress. Isn't that hot enough?
-mark

[BuickBuddy]

It's almost 70 degress. Isn't that hot enough?
-mark

Yes.. It looks like it needs to be recharged.. Frozen low pressure line means either to much freon or not enough.. :TU:

Either that or the air filter is plugged. But that usually causes the inside coil to freeze.

[lsrx101]

Yes.. It looks like it needs to be recharged.. Frozen low pressure line means either to much freon or not enough.. :TU:

Either that or the air filter is plugged. But that usually causes the inside coil to freeze.

Yep. You're right on the money. Another common cause is the evaporator ("A" coil) plugged up with dust (from not changing filters often enough).
A plugged filter or coil will usually also cause poor airflow mostly noticeable in the rooms farthest from the furnace though.

[SS-TRUCK]

Mine did the same thing two weeks ago and was low on freon . Low side pressure should have been about 50 but was only 12-13 . Put the gas in and now cooling great . Has been in low 80s last few days and nice and cool in house .

[sharkmonkey]

I have AC gauges. I'll check the low side.
I'll also check for dust.
-mark

[70aqua_custom]

you're looking for a low side pressure over 62 psi which is about 32 degrees. Below that and it will ice up. The actual low side pressure depends on the outdoor ambient temp and the air temp entering the evaporator.

[12lives]

How do you check a heat pump in the winter? Sorry to go off topic, but while the right people are here I thought I'd ask....

-Bill

[70aqua_custom]

you check them the same way, with gauges, the pressures are different in the winter. You connect your low side gauge to a low side port that connects to the suction line between the reversing valve and the compressor. If you connect your low side gauge to the port in the big line while it's in heating, you'll ruin your gauge in about a second.

[12lives]

Thanks - I thought so. My service guys won't do it until its 70+ outside. I guess I should find someone else!

- Bill

[BuickBuddy]

you check them the same way, with gauges, the pressures are different in the winter. You connect your low side gauge to a low side port that connects to the suction line between the reversing valve and the compressor. If you connect your low side gauge to the port in the big line while it's in heating, you'll ruin your gauge in about a second.


Hehehe.. Blam.:rant:

[SS-TRUCK]

you check them the same way, with gauges, the pressures are different in the winter. You connect your low side gauge to a low side port that connects to the suction line between the reversing valve and the compressor. If you connect your low side gauge to the port in the big line while it's in heating, you'll ruin your gauge in about a second.

Do I understand you correctly , reverse the guage hook up ? What are the readings on a heat pump supposed to be ?
thanks , Mike

[70aqua_custom]

Thanks - I thought so. My service guys won't do it until its 70+ outside. I guess I should find someone else!

- Bill

Bill, I have customers that want me to check their A/C early in the season and I ask them to wait until it gets over 70. You can check the refrigerant charge whenever you want but IMHO it's better to check the A/C when it's warm out and the heating when it's cool out. I'm not sure what your guy is telling you.

Mike, Sort of. The big line becomes the discharge line (high side) in heating. The newer heat pumps will have a third port that will be the low side in heating or cooling. On some of the older heat pumps, the high and low sides switched depending on mode. On the newer heat pumps, the ports on both refrigerant lines will be on the high side in heating, hense the third port. Also, the gauge ports or schrader valves on the outside of packaged heat pumps don't change from heating to cooling.

I also have to correct myself from an earlier post. Freezing, 32*F is 58 psi with R-22 not 62 like I said before.

At 70*F outside temp and 70*F inside temp I wouldn't expect to see lower than 60 psi low side pressure but pressures are only one thing I look at. Superheat is another major factor in determining if the charge is right. The other thing to look for in a central A/C system is a 18*F -+ 3*F differential across the evaporator coil. I take all these things into consideration. The pressures on a heat pump in cooling mode are identical to an A/C.

[SS-TRUCK]

Andy ,
Thanks , I'm not crystal clear , which is normal , but I have a much better idea than before .
Mike

[evil16v]

Mark... you have gotten the answers you need!

[sharkmonkey]

Yeah, this is pretty awesome!
-mark

[sharkmonkey]

Okay, this is the first time I have ever used these gauges. I bought them for the car, maybe they won't work for the home A/C?

The low pressure side has readings for R134a, R404a and R407a. There is also a bar and inHg psi reading.

When I checked the gauge, it was +36 on the R134a scale (if that helps).

[70aqua_custom]

the temperature pressure scales for those refrigerants are irrelevant to your a/c system. You have an R-22 system. Pressure is pressure though so what did the gauge read in psi? If it was 36 psi and the airflow is good and the coil is clear you need refrigerant. You should also install the high side gauge and see where that is to confirm a low charge.

[sharkmonkey]

The center scale on the gauge says inHg. It read 117psi on the low side and about hte same on the high side. It's 65* outside.

[70aqua_custom]

The center scale on the gauge says inHg. It read 117psi on the low side and about hte same on the high side. It's 65* outside.

pressures like that are seen when the compressor is not running. You're going to have to fire up the system, give it 10 minutes for the pressures to stabilize, then read the gauges.

[jay3000]

My outdoor fan was the issue when mine didn't work. It was turning, but wasn't moving much air. It was a quick and simple fix. No heat, no AC either..

[sharkmonkey]

I took the reading after 5-7 minutes. It started out much higher and then came down to 117. I can do it again and wait a little longer. It's cold outside though. I think I'll wait until it warms up again.

My fan works fine. My kids love to put stuff over the fan and let it blow it up in the air.

[70aqua_custom]

I took the reading after 5-7 minutes. It started out much higher and then came down to 117. I can do it again and wait a little longer. It's cold outside though. I think I'll wait until it warms up again.

My fan works fine. My kids love to put stuff over the fan and let it blow it up in the air.

OK, I'm sure those pressures are not accurate. Try closing both valves on your gauge manifold. I think you have them open and the pressure is feeding through the manifold. It's that or the gauges are FUBAR.... lol

[sharkmonkey]

Here's my gauge readings after 25 minutes and 67* outside.

Low Side:
http://i69.photobucket.com/albums/i72/thesharkmonkey/carparts/low.jpg

And High Side:
http://i69.photobucket.com/albums/i72/thesharkmonkey/carparts/high.jpg

[70aqua_custom]

Mark, The same pressures on high and low sides tells me the compressor is not pumping. The first pic you posted, with the ice, tells me it runs and pumps. You also won't make ice with pressures above 58 psi so something is wacky. Do the gauges go to zero when you disconnect them? Are both valves on the manifold front seated, turned all the way clockwise when looking at the face of the valve? If we can't get to the bottom of this here I can walk you through it on the phone. I'll PM you with my cell number.

[GSX-Rated]

I have to hijack this thread, my home A/C is not working either. It is 78 degrees out & the wife is complaining. Here is the situation...

I got a new heating & a/c unit installed last year. A/C worked great all last year & heater works fine. I have gas, forced air duct heat/ac. On the t-stat, I enter a lower temp (60deg) & turn the switch on cool. I can hear the fan running(on Auto) but I look outside & the condenser fan is not spinning. The vents are shooting out air, but not colder than room temp. I took the cover off the heater & on the circuit board, I found a blown auto-type fuse(3amp) I replaced it, still no condenser action. I went outside & took the wiring cover off the ac cond & everything is hooked up & looks fine. there is an override spring-loaded check switch under that cover & I pushed it & the ac cond fan spins, but once I let go, it stops. I called the guy who installed it & he is on vacation. Any Ideas?? I'll take some pics & post em.

[GSX-Rated]

Here are pics of the units.

[70aqua_custom]

Any Ideas?? I'll take some pics & post em.

Make sure the breaker that feeds the condensing unit is not tripped or off. I assume you waited more than 5 minutes for the delay and you see a snowflake or similar symbol on the thermostat? Your system should be under warranty so it may pay to wait for the installer. Nice that he's on vacation. He should have someone covering for him. Can you talk to anyone at his office or will anyone call you back? How long until he gets back?

I can't tell if it's a fused or non-fused disconnect from the pic but if there's any fuses in that service disconnect you can check them with an ohm meter.

[sharkmonkey]

Do the gauges go to zero when you disconnect them? Are both valves on the manifold front seated, turned all the way clockwise when looking at the face of the valve? If we can't get to the bottom of this here I can walk you through it on the phone. I'll PM you with my cell number.

The gauges go to zero when disconnected. I hook everything up with the valves closed (clockwise). Then I open them both up to get the psi readings. Are they supposed to stay closed?

[70aqua_custom]

Then I open them both up to get the psi readings. Are they supposed to stay closed?

Now we found the problem :TU: The valves stay closed unless you are charging, recovering or evacuating.

Did you get pressure on both gauges before you opened the valves? If so, those are the pressures you are concerned with.

[sharkmonkey]

Alright, I'll check in the morning.

[sharkmonkey]

I checked Sunday afternoon and it was around 65* outside. After about an hour of running the low side had 23 psi and the high side had 148 psi.

It never did freeze up this time though.

[70aqua_custom]

I checked Sunday afternoon and it was around 65* outside. After about an hour of running the low side had 23 psi and the high side had 148 psi.

It never did freeze up this time though.

Well, as you probably know, you most likely have a leak and need some R-22. I'd fix it for ya but the travel charges would be a little high....lol

[GranSportSedan]

don't run the system any more until you have the proper charge in it. the refrigerant not only provides cooling for inside your home. it also cools the compressor. if you run it low and it cycles on the internal thermal safety to much it can cause the thermal safety to stick in the open position or worse yet you can end up with a compressor failure due to locked rotor or a burnout..just adding R-22 without checking superheat or sub-cooling is not the right way to charge the system get a professional to repair and recharge.

[12lives]

Here's my update - bad compressor. So you are saying that running it with low charge (mine is PURON) can burn up the compressor? Shouldn't it have some sort of protection circuit? (Carrier - 2 years old)

- Bill

[70aqua_custom]

Here's my update - bad compressor. So you are saying that running it with low charge (mine is PURON) can burn up the compressor? Shouldn't it have some sort of protection circuit? (Carrier - 2 years old)

- Bill

Yes, running with a low charge will overheat, damage and eventually kill a compressor. Different units use different ways to protect the compressor. A compressor thermal overload as mentioned above is found on every unit. Some units use a low pressure switch and some don't. There are other ways a compressor can fail like, factory defects, voltage problems, high pressure and heat, lack of oil etc.

[sharkmonkey]

Am I able to get my hands on some R-22?

[70aqua_custom]

Am I able to get my hands on some R-22?

You need an EPA certification card to buy R-22 and if you have that, you'll be looking at buying 30 lbs of it. Also, R-22 has almost tripled in in price in the last year. With a pressure of 23 psi, you're pretty low. You'll want to fix this leak too because the price is only going up. Low on refrigerant is not the only way to get those pressures and have it ice up but if your airflow is good, low on refrigerant is the most likely.

[GSX-Rated]

My problem was a bad (1 year old) digital Honeywell t-stat.

[70aqua_custom]

Honeywell is all I install. I don't remember having any of the digitals go bad yet. IMHO you had a rare problem.

[GranSportSedan]

I have a vision pro in my home and thats all we install unless the customer is getting a DDC system. we are a commercial/industrial company

[sharkmonkey]

..just adding R-22 without checking superheat or sub-cooling is not the right way to charge the system get a professional to repair and recharge.

Thanks for this advice. I was hoping to add a little r-22 to get me by until the tax return comes.
-mark

[sharkmonkey]

Update:
I had a guy come out and fill it with R-22 for $243. It all leaked out in 4 days.:(

He said he wouldn't fix something this old and sent a sales person to my house who wanted to charge me $3800 to replace the AC unit only, not the heater too. He said he was going to replace it with another R-22 unit instead of the newer kind (whatever that is).

I'm going to have Atlas Butler come out today and give me another estimate and then another local company is coming in right after them.

I really don't want to spend this much money on this thing. We are planning on living in this condo for another year tops, maybe less. Can't they just fix the leak?

[Brad Conley]

$3800 is WAY too much for just the AC. I just had my 80+ furnace and AC unit replaced here at the office for $3900 (struck by lightning a couple of weeks ago). I also got the "new" R4?? in mine. Works better than it ever did.

FYI: I used Bunsold H&C from Marysville. 937-349-3681. They've been in business forever in Marysville and are as honest as the day is long. The lady who answers the phone is Karen...tell her I sent you if you call.

[sharkmonkey]

Thanks Brad.

The sales guy who stopped by the house did not "feel" honest at all. He told me $3800 was the cheapest I would find ANYWHERE. I told him I was going to get a couple of more estimates.

[GranSportSedan]

Post a picture of your A/C if you can. I'll tell you if it's to old to repair. These guys don't want to work for their money,. they see an easy sale and quick profit. find a local Terchnician who is willing to leak check the system and show you where the leak is. that will determine if a repair is feasable or not. one of my biggest pet peaves are so called techs who says something isnt worth repairing because they are lazy. I saved a customer 9000.00 today because another company told them that their compressor was bad and needed replaced. they called us to replace the compressor because they didn't have a good feeling about the other tech..I rediagnosed the problem as i always do even if our own techs were there before me and what on the surface appeared to be a locked rotor(seized) compressor was actually a bad 85 dollar contactor that was causing the unit to single phase and show locked rotor symptoms. my cost on the replacement compressor was 5900.00:eek2: I could have just replaced the compressor at custyomers request but that wouldn't have been doing my job. find a company that actually provides service. Bob

[70aqua_custom]

Thanks Brad.

The sales guy who stopped by the house did not "feel" honest at all. He told me $3800 was the cheapest I would find ANYWHERE. I told him I was going to get a couple of more estimates.

$3800 sounds very high for a condensing unit change out. A 4 day leak should be very easy to find and an honest company should find it and give an estimate to repair it if you ask them to. The leak could be in the condensing unit(outside) or in the lines(rare) or in the evaporator coil. I repair leaks all the time but there are companies that only want to sell you new equipment. You met that guy. Sounds like Brad gave you the name of who you need to call.

If I went on a call where the system was totally empty, which yours must have been if you lost all of the charge in only 4 days, I would NOT add refrigerant until I found and repaired the leak. Did the guy mention that it was empty? Did he mention that what he added might leak right back out? Did he ask you or mention anything about looking for a leak before he charged it? If you answered "NO" to those questions, I'd be asking them for the $243!

[GranSportSedan]

Thanks Brad.

The sales guy who stopped by the house did not "feel" honest at all. He told me $3800 was the cheapest I would find ANYWHERE. I told him I was going to get a couple of more estimates.

new federal regulations mandate all equipment be 13 SEER and that drove the price way up. also you are calling during the peak season so they are charging full price. kinda like buying a hamburger at the fair for 12 bucks when you can buy the same burger for 5 bucks on the outside.

the other refrigerant that is being used now for A/C and heatpumps is 410A.

[GranSportSedan]

Andy
sounds like you learned the right way.. usually when a system is flat i pressureize the system with Nitrogen and a little bit of R-22 and go leak hunting.. obvious signs of oil residue help as well

[buickguy81]

ok first thing do you have R-22 in the unit your testing?. most residential units are these days. I have my own heating company here in NY and I dont think those gauges you have will do what you need them to do.

very first and foremost thing to do is CLEAN everything. indoor coil and the outdoor coil. they work like a car radiator. If it is dirty it cannot disperse or pick up the heat as it should. most times a dirty filter will cause issues also.

If your unit is over 15 years old you could have a bad valve and the unit is letting liquid slip through the compressor. The outdoor unit wont usually freeze unless something is either blocked or pinched off in the line. Thats just my two sense. My advice is make sure its good and clean and then take a amp reading on the compressor wire wile it is running and compare it to the full load amp tag on the unit operation tag. if it is drawing high amps even when clean and the temp outside is not extreme it is safe to say its on its way out.

send me a PM if you wana talk more Id be interested to know what it turns out to be if you wana share.

[GranSportSedan]

ok first thing do you have R-22 in the unit your testing?. most residential units are these days. I have my own heating company here in NY and I dont think those gauges you have will do what you need them to do.

very first and foremost thing to do is CLEAN everything. indoor coil and the outdoor coil. they work like a car radiator. If it is dirty it cannot disperse or pick up the heat as it should. most times a dirty filter will cause issues also.

If your unit is over 15 years old you could have a bad valve and the unit is letting liquid slip through the compressor. The outdoor unit wont usually freeze unless something is either blocked or pinched off in the line. Thats just my two sense. My advice is make sure its good and clean and then take a amp reading on the compressor wire wile it is running and compare it to the full load amp tag on the unit operation tag. if it is drawing high amps even when clean and the temp outside is not extreme it is safe to say its on its way out.

send me a PM if you wana talk more Id be interested to know what it turns out to be if you wana share.
I disagree with thie above. I NEVER clean a unit before i leak check or attempt to locate a leak. oil residue is one of the best ways to spot a leak large or small. cleaning it removes this possible residue and makes the job much harder. Bad valves have nothing to do with refrigerant loss. they simply affect pumping capacity. if the tech added R-22 to the system and it cooled for 4 days then valves are not an issue. also loss of pumping capacity due to bad valve reduces amp draw since there is little or no load on a compressor it does not increase amp draw unless the compressor is on the verge of seizing up due to lack of lubrication.
which compressor wire would you have him take an amp reading from.. there are 3 and only 2 will give an amp reading. the start wire wont tell him anything. once again get a reputable tech out there and you will at least get an accurate diagnosis

[sharkmonkey]

To make this a very short reply...
He did tell me it would probably leak out but would reimburse it if they were going to repair or replace it. To test it with Nitrogen and then repair it was going to cost somewhere around $700. And if it ended up being my "interior coil???" it would cost another $1200. My father-in-law said to call Atlas/Butler and he would pay for the majority of the costs. I called them, they gave me a price $500 less and for the newer 410A system for 12 months same as cash. They are installing it today at 1:00pm.