A solenoid valve coil converts the flow of electrical current into motion to open and close a valve. Electrical current from a timer on an appliance enters the coil and creates a magnetic field that pushes a plunger up in the coil and opens a valve. The open valve allows gas or water to flow from a supply line into an appliance for a set time. Gas appliances such as dryers and heaters use solenoid valve coils as well as icemakers on refrigerators. A lack of gas or fluid flowing through a supply line means that the valve is faulty and sticking in closed mode.
Unplug the appliance.
Remove all panels covering the solenoid valve coil using a screwdriver or an adjustable wrench. The solenoid valve coil is brass, has two electrical connectors and attaches to the appliance on the supply line. Follow the gas or water supply line to the appliance and remove the panels where the line enters it.
Place a pair of adjustable pliers on the nut connecting the supply line. Place a second set of adjustable pliers on the supply line. Turn the nut counterclockwise to loosen it and remove the supply line.
Grasp one electrical connector by the metal end on the valve. Pull the wiring connector off. Repeat this step to remove the second connector.
Turn a multimeter setting knob to the RX-10 setting for a gas valve or to RX-100 for a water valve. Turn the tester on.
Place each of the two tester probes on the electrical contacts removed the wiring from in Step 4. Observe the tester needle. If the needle moves to a reading on the display, the part is working. If the tester needle does not move, the part is defective and needs to be replaced.
When replacing a solenoid valve, it does not matter which colour wire connects to which electrical contact.