Brisk Air Conditioners

The reversing valve is the heart of a heat pump. It changes the direction of the refrigerant flow through the coils, and changes the system from cooling to heating.

The reversing valve’s solenoid can be energized in either the heat or cool mode of operation. DuoTherm roof top heat pumps have the solenoid energized in the cool mode.

One method of checking the reversing valve is to feel the refrigerant line at the top of the inside coil. In the COOL mode, this line will be cool to the touch. In the heat mode the line will be warm or hot to the touch. If you do not feel a cold line in the cooling mode the direction of flow is not correct.

Check the solenoid coil for ohms resistance. The correct reading is approximately 465 ohm plus or minus 10%.