Condenser problem??

[Red]

I have a Heil 5000 hvac system. Live in the south where it's hot & humid. Occasionally when the inside unit cycles off I hear the condenser unit continue running for 30-45 seconds before it shuts down. Seems to happen mostly when the outside temp is mid 90's or hotter. Is this normal? I'm thinking possibly a cooldown for a hot compressor? Or would it be a sticking contactor? It doesn't do it all the time, or long enough to troubleshoot, so I'm left guessing. Any constructive comments are appreciated.

Red

[<kjpro]

Normal? No

Compressor cooldown? No

Lead to costly repair if left as-is? Yes

Get a competent tech out to diagnose and correct the problem.

[Zephyr]

I&#39;d have an HVAC tech. check out the unit. You just may have a sticking contactor and if it&#39;s not corrected soon, it WILL get expensive.

[Jeffrey Lebowski]

If it&#39;s a heat pump then maybe change thermostat setting from ( or to ) auto changeover.

[Bubba]

Are you sure the outdoor unit is actually running after the indoor unit shuts down or are you just hearing the refrigerant still moving through the copper line set? Bubba

[Red]

It&#39;s actually running. I can look out the window and see the fan blades turning. Funny thing though is the relative consistancy of the run-on time when it does it. I would think a sticking contactor would be more variable in time. However I gave the contactor a good spraying with contact cleaner & will see if there is any difference. If none, I&#39;ll replace the contactor. Red

[<kjpro]

Why not call someone that KNOWS what&#39;s happening, that can diagnose the real problem?

[Zephyr]

Kudos&#39;!

[Bubba]

Then you need to replace the thermostat (after the contactor). After all........its almost always the thermostat. Bubba

[Red]

Because as I said in the original post, it&#39;s an "occasional" occurance, as in "once or twice a week and not often enough to troubleshoot". Why pay for a callout when chances are the problem will not occur while the tech is there? My intent for the original post was to ask if a rundown was normal for a hotter than normal compressor and I got the answer of "no". BTW, I have 50 years experience in instrumentation & control circuitry and know well that when an intermittent problem occurs the best you can do is make logical guesses. So I&#39;m guessing a weak return spring in the contactor or the thermostat. You may have other guesses, but at this point I&#39;m going to try mine first.

Red

[<kjpro]

First, I don&#39;t guess, I troubleshoot and diagnose problems.

Second, a competent tech KNOWS what to look for. Unlike yourself, he WOULDN&#39;T have sprayed contact cleaner on the contactor hoping to resolve this issue! And for you having 50 years experience... only shows your lack of training in your own field!