Heat pump / air conditioning problem - help!

Factual Questions
1

Our air conditioner (a Trane heat pump, forgive me if I know little about the right words) is not working. The fan inside the house is still working but the unit outside makes no sounds of life. At first we thought it may be a fuse issue, and sure enough, one was dead, so we replaced it. But it didn’t help. We turn the system back on and hear a click and some humming indicating it’s getting power, but the compressor doesn’t hum to life like it should.

We’ve called a few places to come have a look at it, and they are universally confused when we ask them how much it might cost to repair. They all figure we just want to replace it. Is this normal? Are repairs to these things so expensive you may as well get a new unit? Ours is only 7 years old!

So… what could be wrong with it? I hate the idea of paying a guy ($99 for a half hour!!) to come look at it, just to say yup, it’s dead, need a new one.

Thoughts? It’s a Trane XL 1400, if that helps.

2

You need to ask them if the diagnostic fee is waived if they wind up doing the work to repair or replace your unit. It almost always is.

I recently had my refrigerator die and it was $80 to find out that it wasn’t the kind of dead that can be fixed.

3

Your compressor motors capacitor is bad…disconnect power…replace…restore power…remember AC is a luxury

4

Check for manual reset safety switches usually a red colored push button type swithc with 2 wires coming out. Also check the main circuit breaker for trip…if it blew a fuse at the disconnect then it may have tripped the breaker at the main…make sure by going to the main and locating the 220 feed to the AC disconnect and switching that circuit off then on…

5

If you’ve led a good honorable life, this will be the problem, and it will cost less than $100 to fix. My experience is that the Caps that the local HVAC supply houses sell are junk - get one from a firm that will warranty it for 2 years or more.

6

Checked the breaker, it’s good.

As for reset switches… we can’t find a control panel of any kind on the unit. The heat pump was in place when my fiance bought the house, and he’s been looking for a manual but isn’t having any luck. They sure make these things difficult for the untrained to troubleshoot!

And yeah it’s a luxury. It’s a luxury I very much enjoy having, which is why I am seeking help to get it back!

7

If you have a GRAINGER near you, they may sell you one…Any other HVAC supply house requires you to have a contractors license for orders.

8

Not where I live it isn’t. A privilege maybe, but not a luxury.

9

Im guessing the capacitor, $30 superboost from GRAINGER. Some models dont have a manaul reset, and if it did you wouldnt hear any humming like you said you did…The humming is the indoor unit telling the outdoor unit to turn on…usually you wouldnt hear it due to the outdoor unit’s noise being louder when running…your problem is either no 220 to the outdoor unit, bad capacitor or bad compressor…However, If the compressor was bad, the outdoor fan motor would still run, unless the compressor keeps blowing your fuses every time it starts.
Check the fuses to make sure once again

10

Fuses are definitely still good. I’m not going to start pulling the thing apart myself to try and replace parts - it looks like it’s definitely not made to be opened easily. But I guess it’s worth having a repair guy come out, then.

11

Sometimes if you kick it they start right up

12

I had a similar problem a while back and it turned out to be the thermostat. It appeared to be calling but it was not sending 24 volts to the compressor.

Got a voltmeter?

13

A 2 year warranty on an $11 capacitor?

I’ve never had a capacitor that I’ve installed (all from a supply house) go bad.

14

Good idea.

There is chance that it’s bad cap…unless it’s a pressure switch, or it’s the control board outside, or a bad contactor, or loose wire, or, or, or…

A week doesn’t go by that we don’t run a call with a brand spanking new thermostat on the wall hung by Mr Troubleshooting Homeowner.

Every week.

15

The reason I mention this is my AC quit Sunday night. The compressor sounded like it was locked. I KNEW it couldn’t be the capacitor, because I just replaced it this winter. I had an AC guy friend of mine come out, and sure enough it was a bad capacitor. He mentioned that most of the “consumer” grade parts that the average homeowner can buy from your local HVAC store are junk, and he only buys OEM parts, which are unavailable (or hard to source) for the non-licensed.

FWIW, the original cap had been in the unit for 15+ years.

16

There is a ling list of things that could be wrong.

A good service company should give you a cost. If it is the compressor that is bad get more than one bid. And make sure they are bidding to do the same work.

Guessing on line is only guessing.

17

Here’s another strong contender - The contactor is bad. The contactor is the part that is humming - it is really just a solenoid switch. Oftentimes the contact points in the switch get arc burned to the point that they no longer conduct or ants get in the way of the contacts. This has been the issue with my A/C the last two times I’ve had to repair it. Before that it was the compressor and before that it was the fan start capacitor twice. Good luck and I hope you don’t live anywhere near me - it’s stinking hot here right now.

18

This does not really make sense

19

Which part? It is all true, however I didn’t mention that the problems happened on two different A/C units over the last 13 years. It is my current unit - a 15 yo Rheem that I have had to replace the contactor twice in the last 3 years. The second time I used a beefier 2-pole contactor to replace the OEM single pole that had gone out twice.