Fan runs but compressor has many "false starts"

[lkrav]

I have a one month old 4 ton compressor in the unit outside my home. My service tech installed it as a warranty replacement for an 11 month old compressor that had the same symptoms I'm experiencing with the new one. Earlier in the summer, the coil (in the attic) for this unit was replaced due to a small leak.

Essentially, the unit cools the house fine, but something's still not right. Many times throughout the day (morning, noon, evening... time/outside temp don't seem to matter) the outside fan will come on and the compressor can be heard trying to start. It will kick on for a second, then shut off, and the fan will continue to run. Eventually, the compressor will try again and turn on and do its job.

My tech diagnosed the older (11 mo.) compressor as bad when he came out and watched it do the exact thing I described above.

I am concerned that (a) something is not quite right here - maybe a capacitor issue?... and I don't want to take years off the life of this new compressor by letting this start/stop problem continue... and (b) my outside fan runs quite a bit throughout the day without the compressor along for the ride - so it's wasting electricity dollars.

I need to have him out again to see about this. I feel bad that he may have spent his own money to replace a compressor that might not have been bad. I'd like to speak a bit more intelligently about this problem when I call him.

Any thoughts would be appreciated.

[t527ed]

call him back asap, cycling on the overload is a bad thing.


guess he missed the real problem first time around.........:cool:

[flange]

depending upon system type and matchup, you could require a hard start kit to be added to the system. Check manufacturers specs. My guess is that this is a side jobber who doesnt know the whole stary, and doesnt have the ability to open the catalog and check. Some capacitor fare better than others as well. The way some of the newer capacitors are built, they are not very hardy. i know of a sales person at a wholesaler who had the same problem, only to have his contractor replace the capacitor twice with one from his stock. The third time he called me for advice, and I advised him to buy the most expensive capacitor he had at the same ratings from the manufacurer. He questioned why, and i told him its about the way it is built. Third one was the charmer.

[lkrav]

Should've mentioned one of the few other details I can remember... the compressor is a Copeland.

[lkrav]

Another note as I'm remembering the sequence of events. Earlier in the summer, my tech found a leak in the coil for this system (the coil in the attic unit) when I called him out due to the system not heating & the coils freezing up. In fact, I actually cannot remember this current problem (the compressor "false-starting") existing prior to that attic coil replacement.

Is it possible that the new coil is somehow related/causing this problem? I've read something elsewhere about a txv valve (?) on some coils that brings about the need for a hard start kit.

I think my a/c man is a good guy that does great work. He's not doing it "on the side" or anything like that. He's a full-timer, but he is a one-man shop. Maybe he needed to install such kit when he replaced the coil?...

[ga-hvac-tech]

From your most recent post, the new coil may have a 'no bleed' TXV (TEV) valve in it. This means that the pressure from the compressor is not allowed to 'bleed' off between run times; rather is held. This is one of many little things that contribute to higher energy efficiency.

The problem is that it takes a larger 'UMPH' to get the compressor initially started when there is a couple hundred PSI against it...

On the other hand, if it is a Copeland Scroll compressor, they generally bleed down by themselves.

There may be more going on here than meets the eye...

[laddcoservices]

Scrolls don't generally ever require a start kit per-say, they start in an unloaded position everytime. But, There are times when they are useful to a scroll. (generator power, fuse sizing, etc ) a hard start may be necessary in your situation due to the voltage. Your problem sounds like the compressors start windings drop out before the compressor has relieved the load on the txv. Your techs choices are to replace the txv with one that is designed to work with the scroll, or fight the situations with a start kit... also did The tech replace the run capacitor with the exact match (size) for the compressor. If he adds a start kit make sure it is (3 wire type) and replaces the run capacitor.

[beenthere]

Does your invoice have the model number of the new coil. If so, post it.
From that, should be able to tell if it came with a TXV or not. If its a York coil that is.
York uses Balanced Port TXVs.

He didn't spend his own money per say. Copeland gave him a 12 month warranty on that compressor that he installed last year. And now you have the remaining 1 month of warranty lefton the original replacement compressor.
So you need him to get there ASAP. Or you'll be paying for the next compressor.

[purplesticker]

if the new coil has a txv it needs a hard start

[Tired old tech]

Is comp scroll . Hard start kit for scroll only for effcicency. Most TXV,s NEED hard start kit. Has incoming volt,s checked, what about in rush volts, caps should be changed on any motor replacement weather fans or comps. Has tech checked for split wires. Multiple answers to this ? Need more info to diagnose. No one answer for this unless seen by exp tech on job site

[lkrav]

I checked my compressor last evening, and called a supply house this morning to confirm that it's a recipr., not a scroll. The actual number is CR42KS-PFV-960.

I was unable to find my receipt for the new coil in the attic unit, but I'm pretty sure I can lay my hands on it this evening. If it helps for discussion purposes, the original coil with the leak was a York, or at least was part of my overall York system ("builder's grade") - with the coil at the top of the unit. That's what was replaced.

[ga-hvac-tech]

I checked my compressor last evening, and called a supply house this morning to confirm that it's a recipr., not a scroll. The actual number is CR42KS-PFV-960.

I was unable to find my receipt for the new coil in the attic unit, but I'm pretty sure I can lay my hands on it this evening. If it helps for discussion purposes, the original coil with the leak was a York, or at least was part of my overall York system ("builder's grade") - with the coil at the top of the unit. That's what was replaced.

If you have a recip compressor and a non-bleed type TXV, then you need s hard start kit. Read my post above about back pressure.

Here is a thought for the HO: I am a small company similar to your HVAC guy. I appreciate this forum for the same reasons you do. Get your HVAC guy to join and read/learn here. It will be a win/win deal for all parties!