Home Care Library
Heat Pump (traditional)
Heat Pump (Traditional) Not Blowing Warm Air
The Home Wizard app calculates your ideal home care program to avoid problems with your Heat Pump (traditional), but sometimes trouble can still occur. Here are answers to questions about heat pump (traditional) not blowing warm air.
QUESTION FROM Chuck in Delaware
Have a propane heater with a heat pump (forced air). With the thermostat set to 70 the heater will kick on and so does the heat pump when the temperture drops. Problem is the air coming out of the vents is only room temperture and not hot. Propane heater viewing port shows that their is a flame. Any suggestions?
ANSWER FROM HOME-WIZARD
Dear 'Chuck in Delaware':
Here is a list of possible causes for why your heat pump system is not blowing warm air out of your vents:
1) Outdoor unit iced-up from the weather.
2) Snow drift against outdoor unit.
3) Outdoor unit not running.
4) Cold return temperatures (for example: air handler in attic and the return trunk has disconnected from unit, pulling in cold attic air. Or a unit in the basement with open windows or a flapping dog door stuck open.)
5) Return duct leakage.
6) Low refrigerant charge.
7) Refrigerant flow-related problem, such as a restriction or bad metering device.
8) Poor efficiency (system needs cleaning and servicing).
9) Bad reversing valve.
10) Bad compressor valves.
11) Compressor not running.
12) Running in air conditioning mode.
13) Outdoor unit iced-up from a malfunction.
On the other hand, if this is the first winter season that you are running your heat pump, you may be expecting much hotter temperatures coming out of your air vents than what a heat pump system should be expected to deliver. A heat pump puts out much cooler air than a gas or oil furnace, which most customers are used to. Forced air systems using gas or oil furnaces will put out about 130 to 140 degree air. While a heat pump running on its first stage on a 35 degree day, depending on the return house temperature, might only put out 92 degree air. And on a 20 degree day, it might drop to 85 degrees.
Since normal body temperature is 98.6 degrees, this 85 degree air will feel like "cold" air (since it is lower temperature than your skin). However it is still warmer than the air in your home, so it is still putting heat into the house. Unlike a gas or oil furnace that puts out a lot of heat for short periods of time, a heat pump will put out less heat for longer periods of time.
So if this is your first season with you heat pump, you might want to measure the air temperature from your vents with an accurate thermometer before calling for service.
Hope this is helpful.