If you are experiencing this problem in the cooling mode during the summer, you should probably call for service. This is mostly a winter-time heating complaint.
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. Items in red 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 in red 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.
Hannabery HVAC is registered with the Commonwealth of Pennsylvania's Office of Attorney General: PA#8215
