The modern air source heat pump is a marvel of efficiency and automatic operation. It works well down to 0 F, accomodates snow and freezing weather, and automatically clears away the accumulated frost on the outside coil. That being said, the heat pump does need your assistance to work effectively.
It is important that you clear away any snow that builds up – many times a no-heat call is caused by built-up snow that is stopping the operation of the outside fan. This is important because mini-split heat pumps tend to have fans that blow horizontally and have fairly weak fan motors (unlike the larger American heat pumps that have vertical airflow and more robust fan motors). We have seen these weaker fan motors get burned out by trying to clear snow out of the fan housing or burning up control boards. For some reason, there are no fuses on these units to protect the fan motor or the control board!
It is important to clear away snow underneath and behind the unit as this will help drain away the melted water from the defrost operation.
Our goal is to be Martha’s Vineyard’s premier plumbing and HVAC shop – we appreciate the opportunity to discuss ways to protect your outside heat pump in the winter!