3) Hi. I noticed my that one of my outside heat pump condensing units was laboring throughout the night. This morning I found ice/frost buildup on the heat pump condenser fins. I live in Tucson, Az. It has been colder than normal (below freezing) with a bit more moisture in the air than usual as of late. Can you please tell me what causes this frost/ice buildup, and how I go about rectifying? Does this mean that the condensor pump is shot? I'm originally from the midwest, and have never experienced this before. What should I be doing? Thank you for your help. The answer...............
It sounds to me like you have a heat pump and this is normal for frost to build up on heat pumps. I would guess that in Tucson they set the heat pump defrost cycle times pretty high as it is dry there. If you have a lot of ice build up on the heat pump then there is a problem with the heat pump defrost controls but if the heat pump frost problem is just intermittent then everything is working fine and defrosting as designed.
There are different methods of initiating heat pump defrost but by far the most popular method is timed defrost. The heat pump unit will run for an hour and then automatically kick into the defrost cycle for a predetermined amount of time as engineered by the manufacturer in the defrost control circuit. This is all solid state control by a printed circuit board. Many are the same from manufacturer to manufacturer. The is no big difference from a Trane to a Goodman to a Carrier to Rheem heat pump as far as heat pump defrost controls are concerned. On the heat pump defrost control board there is usually a jumper or dip switch setting where the heat pump defrost times can be changed depending on geographical location and the HVAC technicians professional opinion.
For more info on heat pumps check out my other site http://high-performance-hvac.com and you should find some answers about heat pumps there. Good luck, and remember if you think there is something wrong with the unit then it never hurts to have it checked out by an HVAC pro. It will give you peace of mind. Better a good heat pump check-up by an HVAC Pro can keep you from being cold late at night.
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