Heat pumps are usually covered with ice or frost due to their nature of operation. However, it is not normal for these equipment to be covered with ice on top or inside the coils for longer periods. When there is extreme icing, it may indicate a serious underlying problem which may need urgent attention. Heat pump freeze up may arise if the unit is entirely covered with ice meaning that vital operational controls have failed to eliminated the ice build up. This may trigger operational problems in heating or cooling.
Frost forms around the fins and coils because the unit is cooling already cool air containing some moisture. Basically when the system detects any frost, the process switches to cooling mode. Hot refrigerant is reversed to move through the coils to the outside. This melts any ice and therefore defrosting the system in the process. When defrost cycle is over, the system switches back to heating mode.
Causes of Heat Pump Freeze Up
Because defrost cycle is meant to remove any ice or frost build up, heat pump freezing up may be caused by a fault in the equipment components. If your heat pump freezes up, there might be a problem which may include: low levels of refrigerant, faulty defrost controls, thermostat, and sensors as well as bad defrost relay. Freeze up might also be triggered by sticking up reverse valves, malfunctioning of outdoor motor including improper leveling of the equipment and poor drainage.
Heat Pump Troubleshooting Steps
If you suspect heat pump freeze up, it is prudent to contact a reputable HVAC contractor for professional assistance. Before the contractor comes to your rescue, the following may help you prevent any further damage to the unit. To check for any problem, shut down the unit for your safety. Clean up filters or replace them, unblock indoor air vents and registers, remove obstacles which stand in front of the heat pump coils and most importantly, seal up gutters leaking water directly to the unit.
Following the above troubleshooting tips may help you prevent heat pump freeze up which may lead to permanent damage of your equipment. For this reason, follow us for more articles that will keep your heating and cooling systems running efficiently.