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Carrier Heat Pump Short Cycling

Posted by delanok (My Page) on
Mon, Feb 15, 10 at 13:59

My mother in south Texas has a 3 year old Carrier Heat Pump that is short cycling. It is in heat mode now. It comes on for a minute, then is off for 4-5 minutes and then comes on again, and so on... The bill last month was 3 times normal, and this month was twice normal. The outside unit is a 25HCR360A003 (5 ton 13 seer) and the air handler is FK4DNB006000. It has 15Kw heat strips. The Tstat is s thermidistat CCPRH01-B. It is still under parts and labor warranty, but it is located in a rural area and the local tech is probably not very experienced. The first service call last month, he just re-programed the tstat. I had them back today and he just increased the temp to 76 from 72 and put it on hold instead of the regular program (which was 72 all times). I need some common failure modes to advise them to check. My mother cant afford to be paying extra electric bills and I am concerned this problem will also damage the compresssor. The Tstat is probably limiting the compressor from turning on for the 4-5 minutes, so I guess it is doing its job?

Follow-Up Postings:

RE: Carrier Heat Pump Short Cycling

Something's not right, and running the system like that can be damaging. Sounds like a safety feature is cutting off the compressor each time, possibly due to low or high pressure. They need to ensure proper airflow and proper refrigerant charge.

RE: Carrier Heat Pump Short Cycling


Ryan offers solid advice. This problem needs attention before it causes premature failure of your condenser.

I suggest you find the best Carrier tech in your area who knows their heat pumps. Refrigerant charge is likely suspect. If you are low on refrigerant, you must find out the reason why. Leaks have to be located and repaired if possible.

Post back and let us know what they find.

Sorry for your trouble.

Good Luck!

RE: Carrier Heat Pump Short Cycling

Much like what I thought. I am trying to get it fixed asap. This current tech is fixated on the thermostat and the location, ductwork, etc, all important issues, but should have been addressed when they installed the system and they are not relevant to the problem at hand. I will try another company 15 miles away and see if I have better luck.

RE: Carrier Heat Pump Short Cycling

I'd point them in the direction of checking refrigerant charge. And if it's off, figuring out why (leak somewhere, airflow obstructed to such an extent, etc.).

RE: Carrier Heat Pump Short Cycling

Had same problem 1 year ago and now it is short cycling again. Last year he found small brass connector that was bloced by dirt.

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