Trane XR11 heat pump problem with compressor not always starting right away..

mikebdub

I have a approx 6 year old Trane XR11 split system heat pump that I have recently started having a very intermittent problem / noise with. The indoor air handler runs perfect and about 95% of the time the outside unit will start without issue. I noticed it about 3 or so months ago and sometimes it will happen several times in a day and others it can go for weeks without it occurring. When it happens this is sorta how things go..

The fan on the outdoor unit will start but the compressor will not. It will make a *click click* (sometimes only once or twice and others it will happen 4-6 times) noise and stop. 30 or so seconds will go by and it will do it again then stop. Eventually the compressor kicks on and everything runs fine. The fan runs continuously throughout all of this. At first I thought the *click click* noise was the contactor or something, but if you stand close to the unit you can feel the unit shake a bit so I highly doubt the little contactor is making it shake like that but I guess anything is possible. I opened up the section with all of the connections and everything LOOKS fine. There is a green LED on the board that is blinking normal. All of the electrical connections are tight. The capacitor looks to be somewhat new but I don't have a meter right at this moment to test it but there is no bulge or oil leaking from it. The contacts on the contactor are a bit pitted, but they don't look bad at all (I would have cleaned them but I need to find something small enough to get into it) and I watched it seal in a few times and that seems to be working fine. Of course I could not get the noise to happen while I was watching it but we all know how that works.

Long story short is that everything looks to be in working order so I am looking to anyone who might have any other ideas on what to check or what to do. Like I said this is very intermittent when it happens so what makes it happen is really beyond me. Hopefully this all makes sense haha! Any help or ideas would be greatly appreciated!

I was outside clearing some snow earlier today and it did it 2 times in a row. The first time it did it, it was a solid 3 or 4 minutes before the compressor finally kicked on. *sigh* Ideas?

Edit: I purchased the house about 5 months ago so I am not sure how long this has been going on for before I moved in.

Marty S.

New capacitor would be the place to start. If that doesn't cure the problem put a compressor saver 5-2-1 hard start kit on.

mikebdub

I am really hoping its a capacitor and nothing else. Unfortunately I can't test it (or atleast I don't think I can) with the Fluke 322 clamp meter that I have. I am going to try to get my hands on a multimeter tomorrow but I would really like to figure it out tonight. The capacitor is a Ge Round dual capacitor model 27L33 so would this control both the fan start and the compressor start? And would it make sense that the pump works like it is supposed to most of the time and other times it doesn't if the capacitor was going bad? I guess it would be hit or miss on holding a correct charge if it was going bad..

mikebdub

Also I forgot to mention that when the unit shuts off at the end of a cycle it makes somewhat of the same noise when it trys to start but only for a quick second. It's really hard to try and explain what it sounds like (on start up with the *click* *click* or on shut down lol) I am certain that whatever it is it has something to do with the compressor and not the fan/motor because I can start and stop the fan from the t-stat without issue or noise.

Marty S.

That's correct mike. The capacitor is probably weak being 7 years old. A new one is less then $15 so don't spend more on gas getting a meter that checks capacitors then on the part.

mikebdub

Any idea on where I could pick them up locally? I am seeing $45+ship online and I would not have the slightest idea where to get one otherwise. I am in Belcamp, MD if that helps any.. I have heard that most authorized dealers will not sell to the public and I don't think I can get anything like that from Home Depot and what not. Any help would be appreciate!

mikebdub

It's not really the price that bothers me, I am just extra worried that it is going to cause damage to the compressor if left for another week. Well that and that I am incredibly impatient and I keep sticking my head out the back door every time the heat comes on to see if the compressor is running!

Marty S.

Graingers has capacitors. A local heating and air shopalso will sell you one but the parts wholesale houses will not. Switch to emergancy heat for now, a day or two won't rack the utility bill up too much. The capacitor doesn't have to be a Trane part, just the same mfd & voltage rating. If it's 370V you can get a 440V but not the other way around.

mikebdub

The one I have says 440VAC.. I am assuming that is the max charge it can hold?

beenthere

The 440 volt rating is not a charge rating. It is the internal voltage insulation rating of the capacitor.

mikebdub

ok I replaced with a similar Dayton capacitor from Grainger today and so far so good. Is it possible for a cap to make a unit "sound" like its running smoother? I know it is probably just in my head, but it doesn't hurt to ask right?

beenthere

Yes it is. A weak cap won't let the compressor run at its full speed.