Just like the previous complaint of the heat pump blowing cold air, sometimes the customer just thinks it runs all the time because they aren't used to a heat pump and how they work. In extremely cold weather, a properly working heat pump will run almost continuously. That is the way they were designed to work.

Now, if it isn't extremely cold and suddenly your heat pump just seems to run all the time, this indicates a problem. Along with this usually comes a high electric bill, lower supply temperatures, and sometimes icing of the outdoor unit.

Below is a list of possible causes. Items in blue usually require a service call. the lower items however can be addressed, even fixed by the homeowner.

• Undersized equipment and/or ductwork
• Low refrigerant charge
• Refrigerant flow-related problem - restriction/bad metering device
• Poor efficiency- needs cleaning and servicing
• Bad reversing valve
• Bad compressor valves
• Compressor not running
• Running in A/C mode
• Outdoor unit iced-up because of a malfunction
• Supplemental heat not working

• Outdoor unit iced-up - weather related
• Snow drift against outdoor unit
• Outdoor unit not running
• Thermostat set too low
• Cold return temperatures - example: air handler in attic and the return trunk disconnected from unit, pulling in cold attic air. Unit in basement with a basement return and open windows or a flapping dog door stuck open.
• Return duct leakage
• Poorly insulated house, air leaks

The bottom causes are common problems and can be addressed by the homeowner. Try to check for these conditions first before calling for service.

Hope this helps, remember - these are just rough guidelines and not all possible situations are covered.