How to Repair the Heat Pump Iced Up in Winter?
When heat pumps are iced up in winter do a self check before calling a qualified HVAC technician.
The Problems with Heat Pumps in Winter
Heat pumps are cost effective heating and cooling systems for our homes and buildings. During winter ice may build up over the coil for short periods, but if the ice builds up for an extended period over the entire unit, it indicates that something is wrong with the system. Depending on the settings of the heat pump the ice buildup may defrost completely on every 30, 60 or 90 minutes. If the system does not defrost during the pre set period, it is safe for you to consult a qualified HVAC technician for assistance. However before calling for such a service, it is better to do a self check to solve it by yourself if the issue is not serious.
When building up of ice on the pump is suspected, first mark the time when it was covered full with ice. Then inspect the unit every 30 minutes over a period of 90 minutes. The heat pump normally should start beginning the defrost cycle during this time and melt the ice that has built up. If however the heat pump does not defrost during this time something may be wrong with the defrost control board.
If during a wet weather like rain, snow or fog the heat pump may build up ice faster than usual. Fast build up of ice during a dry weather indicates a decrease in refrigerant levels.
A heat pump can give both cooling and heating. The main components in a heat pump are compressor, one indoor coil and another outdoor coil. During winter the liquid refrigerant in the outdoor coil evaporates the air into gas. The refrigerant condenses into a liquid in the indoor coils. The heat generated during this process is released into the house. In summer the refrigerant evaporates in the indoor coils and the compressed gas is sent to the outdoor coils. It condenses there and releases the heat from the house to the outdoor air.
In the defrost mode the outdoor fan is turned off and the indoor fan turned on. During this time more heat is transferred to the outdoor unit. The electric heater is turned on at this time to overcome cooling and warm the air. If there is cold air blowing from the vents, something might be wrong with the electric heaters or any part connected with. An experienced service person can fix the trouble within a short time and bring your system in its normal state.
Icing on heat pumps may also arise because of the blocks in the coils.Dirts and debris may block the airflow around the coils. Collapsed ducts and dirty air filters can cause various blocks to the flow of air. The flow of refrigerant through the system may be blocked due to a defective metering device. The expert HVAC technician may be able to identify the mechanical faults like broken thermostat, defective blower fan or dirty coil that causes the icing up of the heat pump during winter. If you suspect any of the above faults call the HVAC people for expert assistance and solutions.