| In other words, if you set your thermostat for 71 degrees in the winter and your house only seems to get up to 69 degrees. This problem generates many service calls. And sometimes this is caused by a genuine problem but unfortunately, in extremely, cold weather even a properly working heat pump may have trouble maintaining desired temperature.
Why is this? When it gets below a certain temperature, in our area around 35 degrees a heat pump loses efficiency and cannot keep up with the heat loss of the structure. When the temperature in the house drops approximately 2 degrees below room temperature, supplemental heat comes on to assist the heat pump (usually in the form of electric resistance heaters). When it gets to within 1.5 degrees of room temperature, the back-up heat cycles off and the heat pump continues running tying to reach temperature but cannot. This usually happens when the temperature is at it's coldest - 0 to 30 degrees.
This is however the way heat pumps were designed to operate. Even though they don't put a lot of heat into the house and they run for long periods of time, they are still quite efficient.
So, if it is very cold out and you desire your house to be a certain temperature, you might have to raise your thermostat by 2 degrees to maintain it. Now, if it isn't extremely cold out and your heat pump isn't maintaining temperature, this indicates a problem.
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.
- Thermostat not calibrated/not level/faulty
- 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
- Outdoor unit iced-up
- Snow drift against outdoor unit
- Outdoor unit not running
- Open windows/poorly insulated
- Closed vents
The bottom causes in red are common problems and can be addressed by the homeowner.
Here is a checklist to go through before making a service call:
- Make sure your outdoor heat pump is actually running and that it's not just cycling on the back-up heat.
- If your outdoor heat pump isn't running, check our page on "Outdoor unit won't come on".
In cooling:
This is probably the most common Summer-Time Complaint!
First things first. Please check all of the obvious things before calling for a service-call.
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Is the thermostat on "cool" and turned down below room temperature?
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Is the Power on to the indoor unit? Did you check the breaker?
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Is the Power on to the outdoor unit? Did you check the breaker?
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If yes to these, is the outdoor unit running?
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If no, see if the outdoor unit has a red reset button (most Rheem equipment does, located near refrigerant lines), and push it.
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If that didn't work, see if you have a condensate pump at the indoor unit. If you do, some pumps have a safety switch that shuts off the outdoor unit if the pump overfills and fails to pump. So check the pump to see if it is working.
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If that wasn't the problem, back outside at the unit there usually is a disconnect box mounted on the wall. Some of these have fuses or a breaker inside. If there is a breaker, make sure it didn't trip. If there are fuses, they should be checked. Caution: High Voltage, danger of electrocution. Please do not attempt this unless you are familiar with working with electricity.
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After having checked all of these things and your unit still isn't running, now you can call for service.
If your outdoor and indoor units ARE RUNNING but not cooling, you will most likely need to make a service-call.
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.
- Low refrigerant charge
- Refrigerant flow-related problem - restriction/bad metering device
- Poor efficiency- needs cleaning and servicing
- Bad reversing valve
- Bad compressor valves
- Duct leak in unconditioned space
- Clogged air filter
- Outdoor coils blocked or very dirty
- Open windows/poorly insulated
- Closed vents
- Humidifier running
Hope this helps, remember - these are just rough guidelines and not all possible situations are covered.
Hope this helps, remember - these are just rough guidelines and not all possible situations are covered. |
