The heat pump is built to shrug off frost; an automatic defroster in the system should melt away the frost every hour or so.

However, if the frost persists hour after hour and becomes ice, you will need to take action to prevent the heat pump from freezing.

• Look around the outside unit to make sure snow, ice or debris are not blocking it. An outside unit needs a clear area around it – two feet radius preferably – to keep the airflow functioning well.

• Dirty air filters are another common, easy-to-fix problem.

Other causes are more complicated, such as low refrigerant or defective components.

In those cases you should call an HVAC technician, especially if the emergency heat comes on frequently, indicating a serious problem.

Heat pump problem in Queens? Premier HVAC’s technicians are experienced, licensed and insured.