No power or defective solenoid

Check if there is power on the solenoid during a freeze cycle. You can also apply 220VAC directly to the solenoid in order to test the operation. You should hear a distinctive “Click” each time power is applied and removed.

Common causes to have a fault with the solenoid are either a burnt-out solenoid, no power or a jammed plunger in the valve itself.

To test the solenoid, 220VAC can be applied directly to the solenoid valve. An audible click should be heard.

• If there is no clicking, there is a good chance the electromagnet is faulty which can be repaired by replacing the electromagnet, and not the entire valve.
• If the plunger is stuck, you can try to strike it with a solid piece of wood to test it, however, it would be best to replace the solenoid valve completely.
• If there is a clicking sound, this indicates that the valve is operating correctly and the fault may lie with the wiring or the thermostat or switching devices such as relays.

It will affect how the HP/LP sensor operates which can either prevent the HP/LP sensor from detecting a pressure drop when the solenoid opens or detect the increase in pressure if the solenoid is closed.

Leaking valve

If the solenoid valve is closed (off), especially when the freezing cycle is on hold or if in defrost and you notice ice building up on the outlet side of the valve, this indicates that the solenoid seal is worn and is leaking.

You will have to replace the solenoid valve if this is the case.

This can cause the compressor to short-cycle (turn on and off at irregular intervals) which may cause harm to the compressor unit.