Can anyone tell me how to test the soleniod for the reversing valve on a heat pump? :confused:

You can use an ohm meter to test for continuity of the coil. You should have a certain amount of resistance. If the meter indicates no resistance, then the coil is open, and it will not pull in.

Be sure the power is of to the unit, and disconnect the two solenoid coil wires to gain access for this test.

If the resistance is very high, then it still is open .

You may be able to determine the typical resistance if you can find the manufacturer and check their website for technical data.

Or if your up to it, you can disconnect one wire, energize the coil, and test the disconnected wire coing from the coil for voltage with a vlotage tester. If no voltage, then the coil is open.

Another test would be to have somebody switch the system while you check the valve. You should be able to hear or feel it activate.