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how to check the capacitor on a rheem heat pump to tell if it is good or bad?

the unit was working fine and now the fan will run but the compressor will not kick on. I have check the contact opening and there is no blockage between the points. I have had "critters" get between the contacts and the compressor would not kick on.

Public Comments

1. Bugs clogging the contactors are very common, but If you cleaned them out and your system still won't start -- then there are other problems. It is true that start & run caps can go out without warning, but if you do not know how to check your capacitor on your unit, you should really call a professional. We own a small HVAC company and many times a homeowner will start "fixing" their system -- and end up shorting something in the process which in the end costs them more than if they had called the professional in the first place. I hope this helps -- good luck!
2. If critters have gotten in the movement of the contactor it is possiable that the magnetic coil that pulls the contacts together is burned even if they have been cleaned out. read the voltage (on the coil section of your compressor contactor) and uses a meter to see if that proper voltage is on the coil. If it is..the coil is bad. I would replace the contactor. But if the voltage is not on the coil, there are other devices that will open the voltage to the contactor coil. they are wired inseries with the coil and are there for protection. Head pressure control, low pressure control, freeze protection control,current overload control,internal thermal overload in the compressor. Also as you say th capacitor for the compressor. if single phase it probably has a starting capacitor and relay. The capacitor can be tested with the use of a capacitor tester. Or you can use a multi-meter with capacitor unwired and safely discharged by shorting terminals, check for open circuit between the poles on the capacitor. Then check terminals to the case of the capicitor to see if it reads OHMS to the case (indicates shorted to ground). If both are ok.. use a scale on your meter (ohms) which will build a number and slowly bleed down. if It wont bleed down its shorted internally if it bleeds down slow..itis probably ok..if it bleeds down fast it is probably bad. be sure to discharge the terminals after each test. these are general test items but many other things could come into play like broken wires in the control circuit. (Squirlls are famous for chewing wires into) I hope I gave you some insight. I welcome others to give their input too. Good luck friend Rangefinder
3. voltage meter