I am in Charlotte NC area and friday we had a cold rain all day, temps in the 30s. When I left my house I set the thermostat to 67 and went to work. When I got home the heat pump had a sheet of ice on top. It worried me because thats where the fan blows out. But its pretty new so I thought maybe its normal. My neighbor has same one and his had no ice. I went inside and turned heat up to 70. 3 hours later it only had gone up 1 degree. I went outside and broke the ice off. So is that not normal?
Turn on the aux heat now. It will melt the ice with hot refrigerant to the coils. You'll need to call someone to test the defrost circuit.
if the ice is in bands around the unit its low on refrigerant put in emergancy heat and call a tech
Note that when there is a wide temperature differential, e.g., when an air-source heat pump is used to heat a house on a very cold winter day, it takes more work to move the same amount of heat indoors than on a mild day. Ultimately, due to Carnot efficiency limits, the heat pump's performance will approach 1.0 as the outdoor-to-indoor temperature difference increases. This typically occurs around ?18 °C (0 °F) outdoor temperature for air source heat pumps. Also, as the heat pump takes heat out of the air, some moisture in the outdoor air may condense and possibly freeze on the outdoor heat exchanger. The system must periodically melt this ice. In other words, when it is extremely cold outside, it is simpler, and wears the machine less, to heat using an electric-resistance heater than to strain an air-source heat pump. so on cold days if its going to be close to 30's throw the day I just turn my thermostat to emergence heat,, and if its going to be cold for a week or so I just turn the breaker off to the heat pump instead,
