I just got a new Trane heat pump system installed (air handler and outside unit) 6 months ago. The weather has been around 32 in these parts for the last few weeks and in the 50/40s before that. During this period the heat pump periodically blows cool air for about 10 to 30 minutes and then reverts to warm air again. I usually keep my thermostat between 60 to 65 degrees.

The technicial from company that installed it told me the outside unit starts to freeze when the outside temperature dips below 40, or when it is humid, or rainny. Per technicial, when these weather conditions occur and the unit freezes, it needs to go into a mode to defreeze which lasts about 5 minutes every hour or so.

Can this possibly be correct?

Why is the outside unit freezing when it is below 40, or humid or rainny, not when it is just below 32?

Shouldn't emergency heat kick in when the defrost cycle kicks in, thereby allowing warm air to blow?

Is cool air blowing up to 30 minutes normal? If not, what is normal?

It seems having to defrost every hour is too frequent for a 6 months old unit, or not?

I appreciate time and help:)

Energy Savers: Air-Source Heat Pumps (http://www.energysavers.gov/your_home/space_heating_cooling/index.cfm/mytopic=12620)

HowStuffWorks "How to Troubleshoot a Heat Pump: Tips and Guidelines" (http://home.howstuffworks.com/home-improvement/heating-and-cooling/how-to-troubleshoot-a-heat-pump.htm)

Can this possibly be correct?
Yes

Shouldn't emergency heat kick in when the defrost cycle kicks in, thereby allowing warm air to blow?

Yes usually

Is cool air blowing up to 30 minutes normal? If not, what is normal?

Not really there is NO normal. It depends upon how the heat pump is setup and how the thermostat settings are set for the thermostat setup in the thermostat instructions.

.It seems having to defrost every hour is too frequent for a 6 months old unit, or not?

Defrost depend upon settings on the defrost board in the heat pump unit. It makes NO difference how old a unit is since the setting used are usually for a specific area of the country with specific weather patterns.


The outdoor unit extracts heat from the outdoor air. When temperatures hit a certain level the unit will freeze since the temp of the unit coils along with the moisture in the air cause this to happen.

Thank you for your response!

Is it normal for outside unit to freeze duing rain or huminity as well?

Given the original response, should I bring this to the technician's attention?

Actually you should be asking the technician all these questions since he or she has a better idea of what was installed and how it was setup.