Heat Pump Troubleshooting Advice. When you have a problem with your heat pump you want to check the basics. Anything beyond that you really need to call in a professional to troubleshoot the heat pump. The heat pump or any type of electrical mechanical equipment you have problems with and need to troubleshoot. Whether you call for heat pump troubleshooting or any other repair there is only so much you can do.
Heat Pump Troubleshooting Advice
Before calling a heating and air conditioning company, check the following:
- Power Supply
- Ice or Freezing
- Air Flow
- Condenser Fan Motor
- Refrigeration Problem
A basic description of that list is found below. This is designed to give you the basics of heat pump troubleshooting.
1. Heat Pump Thermostat
Check selections on the thermostat. Ensure that it is set to the desired settings. I’ve responded to service calls where the homeowner made a no heat or no cool call. I found they had the thermostat set to heat when they wanted to cool. Or set to cooling when they wanted heat. Additionally, make sure the set point is correct. For example, if you want heating, make sure the thermostat is set to heat. Furthermore, if the temperature in the house is 65° F make sure you turn the thermostat setting up above 65° F. to get heat. Finally, for heat pump troubleshooting this is always the first place to start. At the thermostat.
2. Power Supply
Check power supply. This can include a circuit breaker and or/a regular looking wall switch close to the unit. This is another easy fix. I have responded to no heat or no cooling calls only to find the power was turned off inadvertently. Perhaps relatives were visiting and someone mistook the wall switch for a light switch. These switches are typically not on heat pumps as a heat pump liking has a breaker next to the heat pump. Make sure you check the breaker at the air handler and the breaker in the main panel. A typical split system will have separate breakers. One for the condenser and one for the air handler. Step 2 in heat pump troubleshooting is to check the power supply.
3. Ice or Freezing
In the summer check for freezing up of the heat pump. If the air heat pump unit is frozen turn it off. Check the air filter(s) to make sure they are not clogged or obstructed in any way. In the summer if the evaporator coil has ice on it or any of the copper pipes have ice on them then you have a problem that needs the attention of a professional. If you find no problems leave the unit turned off and call a service company.
In the winter, check the condenser (outside unit) does not have excessive ice on the coils. This could mean the defrost mode isn’t working properly and may need a minor adjustment or a repair altogether. It is best to call a pro to fix that issue. Step 3 for heat pump troubleshooting is to check for ice or freezing.
4. Air Flow
Is the air handler blower working good and blowing air out of all of the supply vents? If not or it is weak then you likely have an airflow issue. Always make sure you have a clean filter and that all of your supply vents are open and unobstructed. If this is all good then you have another problem with the airflow. Maybe a bad blower motor, the unit is freezing up inside the evaporator coil or collapsed ductwork. In any of these cases, it is time to call an HVAC repair service. Bad air flow indicates a serious problem. Step for in heat pump troubleshooting is to check the air flow.
5. Condenser Fan Motor
Is the condenser fan motor turning at the heat pump condenser? Word of note - sometimes in the winter or when you have the heat pump in heating mode the fan will not turn while the compressor is running. This is normal and a part of the automatic defrost mode for the heat pump. If the fan is not turning but you hear the compressor running then something is wrong (unless as noted above with defrost mode) and you need to call a professional. Step 5 in heat pump troubleshooting is to check the condenser fan motor.
Heat Pump Diagnosis & Repair
Additional Helpful Troubleshooting Hints
- Always change your filter on a monthly basis
- Make sure all your supply vents are open and unobstructed
- Keep area clean around indoor unit especially the return grills
- Keep outdoor condensing units free of leaves, grass, and debris including trash cans and/or children’s toys or playthings like small plastic pools or playhouses. Additionally, your service technician will appreciate you not planting holly bushes near the outside unit
- Have air conditioner, heat pump, or furnace system serviced every six months
Heat Pump Troubleshooting Flow Matrix
|Heat Pump Troubleshooting Flow Matrix|
|Problem Process or Component||What to Check/Do for Troubleshooting|
|Thermostat||1) Check the settings of the thermostat. Make sure it is in heating mode and the set point at the desired position.|
|2) If you have an older mercury switch type of thermostat make sure it is level.|
|3) If you have a digital thermostat and the display is blank then you have either a bad thermostat or a power problem. Likely this is a power problem. Check all the power switches for the system including the circuit breakers. Call for service if that doesn't resolve the problem.|
|Power Supply||1) A heat pump can have several different breakers. In the main circuit breaker panel you should have one for the air handler and one for the condenser. Both of these need to be on. If you reset the breaker and the heat pump breaker trips again then you have a serious problem and need to call for service.|
|2) Additional to the main panel breakers you could also have breakers or fuses at the air handler and the condensing unit. Check these after checking the main panel breaker box. Again, if you reset a breaker and it trips again you should call for service. Same thing if the system utilizes fuses instead of breakers. If the replacement fuse blows after replacing the blown fuse you need to call for service.|
|3) Control Power - this is the control power that comes from a control transformer. The control transformer gets it voltage from the main power supply. If everything is okay with the main power supply (no blown fuses or tripped breakers) and the display on the thermostat is blank(as mentioned above) then it is possible you have a control power problem. This can occur with a blown control fuse or blown transformer. Often this is a direct result of a dead short in the wiring Call for service.|
|Ice or Freezing||1) Ice or freezing of the condensing unit can be because of a problem with the defrost cycle. The quickest way to solve this problem and get heat is to turn the thermostat to air conditioning mode. When the ice is gone turn the thermostat back to heating mode. Then call for service.|
|2) Ensure there are no obstructions around the heat pump condensing unit located outside. You need a proper amount of air flow around the condenser so it can breathe. The heat pump pulls air from the outside air even when it is cold outside. It then delivers this heat inside to keep you warm.|
|Air Flow||1) Always ensure you have the proper amount of air flow inside. This means making sure you have clean filters. Clogged and dirty filters can cause severe issues with air flow and that can cause it to malfunction. A regular filter maintenace schedule should be made and adhered to year round. Check the filter and change as necessary.|
|2) Low air flow with clean filters could mean you have a problem with the blower motor. The blower is about to go bad, is bad, or another component that controls the blower has malfunctioned. Call for service.|
|3) The duct work has collapsed or is restricted. Make sure all your supply vents are open. Visually check the duct work to make sure nothing has caused it to collapse or be restricted.|
|Refrigeration Problem (Advanced Problems that will require a service call)||1) A low refrigerant charge can cause problems with a heat pump and providing good efficient heat. If you have noticed the heat pump has been struggling and the temperatures outside are not terribly bad you may want to call for service to have it checked.|
|2) Compressor is not working. This can be because of a bad component for the compressor such as a capacitor or contactor. It could also mean a bad compressor. Call for service.|
|3) Defrost Problem. The defrost board could be bad or something else causing it not to function properly. Call for service.|
|4) Reversing valve problem. The reversing valve switches the heat pump condenser from heating to cooling. Call for service.|
|5) Bad condenser fan motor. Call for service. Note that some heat pumps, when in the defrost mode, the condenser fan motor will not run.|
Heat Pump Repair Advice Advisory
When you read information on the web double check that the information is correct.
I read this directly from an un-named article on the internet that has a number one position in a search for troubleshooting heat pumps – “check the heat pumps ignition”. What? Can you say that one more time? It is obvious to me the person who wrote that article has never touched a heat pump in their life and should have never written an article for troubleshooting heat pumps. Can someone please tell me where the igniter is on a heat pump?
I’ve was out of the field for a year doing management work and now I am doing engineering work and occasionally going out to the field but I do not think the basic concept of heat pumps has changed that much to include adding ignition systems to heat pumps. If you are going to troubleshoot your own heat pump then please follow the basics above. Beyond that please call a professional to repair your heat pump or troubleshoot your air conditioner.
Turning Faulty Advice into Good Advice
Some other faulty advice from around the web:
Heat Pump Troubleshooting Advice – “Most of the time when your heat pump doesn’t work it is a faulty thermostat”. I’ve been on many service calls and I have found faulty thermostats. Most of the time the reason for a faulty thermostat is because the homeowner thought the thermostat was bad and the decided to change it. Changing parts, especially the thermostat, simply doesn’t work most of the time.
Whatever reason the homeowner didn’t wire it properly or they didn’t turn the power off and crossed the wrong wires and burned up the heating anticipator or blew the transformer. Unless you have had a lightening strike, major power surge that took out other electronic devices in your home, or someone took a hammer to the thermostat then your problem is probably not the thermostat. If you have problems with your heat pump or air conditioner and want to troubleshoot the problem yourself simply check the settings of the thermostat. Make sure it is set to the appropriate setting. Double check to make sure it is set to the appropriate setting.
Parts Changers Rarely Make the Repair
If everything is correct then you are done at the thermostat. Don’t run down to your local hardware store and buy a new thermostat for your heat pump thinking it will solve the problem. Chances are, if you doing it as a part of the process of finding the problem with your heat pump then you will probably still be cold after changing the thermostat in the process of troubleshooting a heat pump. You can change every single part in the heat pump system and still have a problem with the heat pump. Furthermore, changing parts, especially the thermostat, simply doesn’t work most of the time.
Heat Pump Troubleshooting Advice – “The motor may need to be reset” is another thing that struck me from reading this article for troubleshoot heat pumps – Reset the motor? I have not seen many blower motors that have a reset button on them. There are very few out there that have reset buttons on the blower motor but chances are you do not have the type of motor that has a reset button on it.
It seems to me the person who wrote this article read an article on oil furnaces or boilers and tried to adapt it to troubleshooting heat pumps. Oil burners have reset buttons on them but not on the blower – the reset button is on the burner as a part of the burner ignition controls. If there are any manual reset buttons on heat pump it is possible there is a manual reset button on the condensing unit. Furthermore, I know of only two manufacturers that have these reset buttons on their heat pumps. Rheem and Ruud.
To Reset or Not to Reset
This is not a reset button for any motor but a high pressure reset switch. If this switch needs to be reset on a heat pump it means the head pressure or the high pressure side of the heat pump is exceeding maximum pressure and is killing the unit as it should to avoid damaging the compressor or other components in the refrigeration loop of the heat pump. This means one of several reasons if you are repairing the heat pump. Furthermore, the condenser coils are plugged up with trash, dirt, or other debris like grass, the condenser fan motor has failed, or there is a refrigeration problem such as an over charge of refrigerant in the system.
Heat Pump Troubleshooting Advice – “Heat Pump trips the circuit breaker” – they tell you to check the heat pump circuit breaker in this bad article. Which heat pump breaker do I check? A real heat pump has two circuit breakers in the circuit breaker panel for the home and if the heat pump has electric back up heat then it should have another set of breakers or fuse protection at the location where the heat strips are which is usually in the air handler.
Yes, a real heat pump (not the fictional dream heat pump they describe in this heat pump repair article) has two circuit breakers. One for the heat pump condenser and one for the air handler. If the breakers are tripping on the heat pump circuit then you have a dead short somewhere in the system and it needs to be addressed by a professional.
“Air Handler Squeals” – they tell you that it is usually the belt. Huh? In the residential market HVAC manufacturers went to direct drive blowers many, many moons ago and stopped distributing units that are belt driven. 99.9% of heat pump air handlers out there installed in homes are direct drive. Finding a belt driven blower in residential systems is akin to to finding a Model T. If your heat pump this old it is time to replace the system and not the belt.
Advice | Heat Pump Diagnosis & Repair - Conclusion
Okay, I’m done commenting on that bad article for finding and fixing a problem heat pumps. Some of the information in that article is okay although general knowledge. If troubleshooting heat pumps is your profession please go ahead and fix it. Chances are you are not a professional HVAC technician so please check the basics. Furthermore, leave it up to the professional HVAC Technician to troubleshoot the heat pump.
High Performance HVAC Heat Pump Troubleshooting and Repair Advice