Help! A/C runs constantly but not cooling! Update 7/24

[MineMail]

I had the exact same thing happen last month. The a/c was set for 79 and the upstairs temperature was 85 when I went up to bed. The fan ran constantly until we turned it off. The next morning, I went outside and checked the circuit breakers. They're in their own box mounted to the exterior of the house, near the two units. (We have two zones) Sure enough, one of the breakers had been "tripped." I turned both to "off" and then back to "on" and haven't had a problem since, even with temps in the 100's.

Try this before you do anything else. Saved me a service call fee.

My cousin is an HVAC specialist who says that it happens when there's a lot of electricity demand or storms. The power coming into the house has spikes or brownouts that you might not notice in the lights, but are enough to trip the breaker. If it happens more than once, then he said to check all the connections because it could be a wire has loosened up due to heat. I am not going to do that - I'll buy him dinner in exchange for his making the 45-min trip to my house, lol.

 

[bdcp]

We just had to replace the entire thing for our house in KY. Six year old house, and we found out the units were at least 8 years old. The homebuilder put used units in the houses AND ours were mismatched for size. The AC guy said it is quite common for homebuilders to put used units in.
This is one more thing for us to watch for next home we buy.

Maybe it's common for that builder, but it is not common for most homebuilders to put in used units. We have owned 3 new homes over the last 30 years, all by different builders, in two different states and all our units were brand new. Units should last more than 8 years also.

 

[MommyTo5]

That's what I was thinking too. We have 3 units and last summer we had to replace two capacitors and if it wasn't for our service contract it would have been over $200 each. Yes, you got a deal. The part isn't that expensive, but the rate to install it is. You can buy one and install it yourself. Apparently, it isn't that difficult and there are instructions on line. My DH would rather pay someone else to do it though

I was thinking the same thing! This happened to us last Summer. The heating/AC company we had used in the past wanted to replace the entire outside unit (we just had the AC coil replaced 3 years ago when we replaced the furnace), but I told the tech that we absolutely did not have the $. We recently stopped using credit cards and were paying cash for everything - at the time, we didn't have several thousand $ sitting in the bank! Anyway, once I told him this, he admitted it was really just the capacitor that needed to be replaced (it was leaking) and that I could probably order it online for $60 or less and we could do the simple repair of pulling the old one out and putting the new one in ourselves. We thanked him for the info and he left without billing us for the visit. We went out to the unit, wrote down the #s off the capicitor and did a web search finding the part at Grainger (they have a website) just a few miles from our house for less than $25!!! The repair was super easy... disconnecting wires from the old part and connecting them to the new part. It took all of 10 minutes. I was in tears when the AC kicked on... could not believe that we accomplished the repair ourselves and literally saved thousands of dollars!

Good luck, OP!

 

[KarenAylwood]

Same thing happened to us about a month ago... it was just the circuit breaker. It got tripped somehow when we were gone and we reset and it's been fine.

I hope it's not an expensive fix!! Goodluck!

 

[North of Mouse]

We've had this happen to us a few years ago, and luckily it just needed freon. But I definitely would turn the unit off. If it's not cooling, the compressor and fan do not need to be running all the time. Unfortunately, if it is the compressor, that could mean $$'s, and sometimes it pays to "bite the bullet" and put in a new unit. The newer ones are much more efficient. Hope for you that it just needs more coolant

 

[doris1976]

More then likely the compressor. Ours went out and tried the freon first but the compressor had a leak and it was gone in two days. Ended up buying a whole new unit....4000.00 ouch!!!!

 

[FoundMyPrince]

Our a/c died today. It's been crazy hot here; 104 today. It seems like my a/c has just run non-stop for the last month. This morning the vents were blowing cool air, but not cold. I noticed the fan outside (we have a heat pump) wasn't spinning.

1 - check breaker box (all good)
2 - clean filter (was cleaned last month)
3 - look for reset button (couldn't find that)

Still not working. Called the a/c repairman - was here in an hour! He looked at the unit, asked for a water hose as the fan motor was overheated. He sprayed it with water so it was cool enough to work on. Turned out we needed a new fan motor.

$90 labor
$300 fan motor

Our house was up to 101 degrees this afternoon. Right now we're at 89!

 

[dhardawa]

Waiting until next Tuesday is ridiculous! I would call different companies until someone is able to come more quickly. Mine did that a while back and I believe it was one of the fans, but it could also have a freon leak and have nothing to cool with.

I totally agree with this!!! Waiting until Tuesday is absurd. Call around. My HVAC people would be there within a few hours. When your air stops working, they consider that an emergency call and get right to you.

 

[thebeesknees]

Thanks to everyone for their advice so far. We have tried what was suggested to no avail (breaker box fine, new filter, no clogged lines that we could see). DH talked to a friend last night who walked him through a few things over the phone and then said it sounded like we definitely needed a pro to come take a look as the basic stuff checked out. There is electricity running to the unit, but the motor outside isn't coming on at all. The air we felt indoors was apparently just from the fan, not the A/C. I'll be calling around to see if I can find someone to come look sooner. The unit isn't terribly old (installed 2004), so I guess we'll see what is diagnosed before we decide whether or not it is worth it to replace. Fingers crossed it isn't too expensive as we have had a string of other emergencies lately that have made our bank balance shrink quite a bit!

 

[Ginny Favers]

Most likely it just needs more coolant as you have a leak. We have this problem every year. It costs big $$ to find the leak, and when they do, even more to repair (and it doesn't always fix the problem as leaks can be hard to locate and repairmen inept), so we just refill it and let it chug away for the summer. Coolant now is VERY EXPENSIVE because they don't make the kind that's in old a/cs anymore-- they make a newer, greener kind.... so every year we get it refilled, it's more and more expensive. This time, it was $500 to refill.

We're getting a new, high-efficiency one next week. Whatever you do, make sure you get a reputable person as there are a lot of repairmen who don't know what they're doing.

 

[goofy78]

You need to actually change the fuse inside the breaker box. Did you try that? I know you said the box looks good but the fuse has to be changed in order to see if that's the problem.

 

[Tinkh]

Have your husband google a video on how to change your capacitor. Our guy changed ours for 75 dollars and ours was doing exactly what yours did.

 

[mulanshaircut]

This happened to us last weekend. It was a blown capacitor. It's safe to leave just the fan on to circulate air. Just make sure to turn the a/c part to off.

My family was in the HVAC business for 30 years and during the busy season it might take 4 or 5 days to get to all service calls. We lived in a small city and there weren't a lot of companies that did that kind of work.

 

[riley2008]

Good luck on finding someone before next week. Around here it's a week before anyone can get to you, too. Just the nature of the demand versus supply. Great demand for those HVAC people this time of year.

We found a reputable company that we now maintain a service contract with. For $200/year, they come come in March to check the AC and in September to check heating elements. We also get "priority status" for response during peak months if anything were to go wrong. (Not exactly sure what "priority status" means, but it sure sounds good. Hope we don't ever have to find out.)

 

[Elleshoodat]

We had the same issue a couple of weeks ago and had to have our fan motor replaced. Luckily our A/C parts are still under warranty, so we only had to pay labor (not that anything should be breaking in the first place; it's only 2 years old).

Like other PPs, we have a maintenance contract with a repair company and were able to get same-day service.

 

[HeyIt'sMe]

I've seen a few posters mention the capacitor. When we had our annual A/C tune-up this Spring the technician mentioned that we might want to replace our capacitor next year when we have our tune-up. He said there weren't any indications that it was ready to give out but based on the age (our house is 9 years old) it might be a good idea to replace it. He said they don't usually give any signs they are ready to stop working they just stop. I don't remember what he quoted but it was under $200.

I hope you get your A/C fixed soon!

 

[jiminykrikkit]

Oh man, I'm so sorry. We're actually going through the same thing right now.

Tuesday night was bad because we were so hot, then we realized Wednesday that the AC wasn't cooling the house, and it was up to 82 by the end of the day (could have been worse, but we thankfully had some rain for a while! It's usually in the 100s here during the summer!). So DH looked at it and there was ice on the lines (?). We shut down the AC but left the fan on so it would blow the warm air over the ice to help thaw it. That was for the majority of the day on Thursday. Turned it back on Thursday night and it started cooling again. We're not sure if it will ice up again, but we'll see. Today it's sunny and hot outside but the house is still at 76 (what the thermostat is set for) and it's nice and cool inside.

My suggestions to stay cool in the meantime is to turn on all the ceiling fans and keep the doors shut to keep as much cool air inside those rooms as possible. And keep all the blinds closed and curtains drawn. Also limit the use of large appliances (oven, TV, etc) to keep the heat down (you wouldn't believe how much heat your TV can give off depending on size, etc). Also keep as many lights off as possible. And of course, just leave and go to the library or walk the mall or something.

Unfortunately, last year the same thing happened to us and it was the compressor. Our house is fairly new construction so the compressor happened to still be under warranty (just barely) so we only had to pay for the labor (I can't remember now how much it was, but I think they quoted around $7k for the whole job, if we would have had to pay for the compressor out of pocket).

We're working on getting them back out here to check everything, it hasn't even been a full calendar year since the last repair...so it doesn't seem right that it's broken again.