Testing Furnace Gas Control Valve

Pull the wires off.

Testing furnace gas control valve.

If solenoid valves are malfunctioning dangerous pressure might build up and cause damage. Standing pilot gas valves. There are four possible reasons for solenoid valves malfunction. Some gas valves cannot be checked with an ohmm.

I will be checking various gas valves to see if you can check the continuity of the solenoid with an ohmmeter. Check to see if you re getting 24 vac at the terminals on the gas valve. Wait for the unit to cool if it has been in use. Locate the hot surface igniter and look for a spark or glow there.

Locate the gas valve. If the appliance is a boiler or furnace it ll use 24 vac to operate the main valve. Take out the bolts in the service panel on the side of the furnace using a nut driver. Most gas dryers have pullout snap panels.

If so and the boiler or furnace isn t firing up then you need a new gas valve. Turn off the furnace at the wall control. The difference is the standing pilot gas furnace always has a pilot light on. Turn off the gas feed line valve to the dryer.

Coil burnout failure to open failure to close or solenoid valve noise. Even though these systems are generally built to last gas furnace valves are the parts more likely to need replacement over the life of the furnace. How to check the furnace gas valve with a multimeter step 1. Everything that applies to the electronic ignition sequence of operation by the way of the safety circuit must be proven before the gas furnace will allow the gas valve to fire the main burners to provide heat.

This valve is usually found in the wall line leading to the dryer and is shut off by turning the handle perpendicular to the gas line. Turn off the gas supply valve to your appliance to test whether your valve is capable of shutting down properly. There should not be a flame up there if the valve is working correctly. Testing gas pressure at the valves is often the first thing hvac technicians do when they are called in to check on faulty furnaces.

If you do get voltage then i would be testing for gas pressure before the gas valve and the manifold pressure when the gas valve has voltage. Set the thermostat or the device s controller slightly above the current room temperature. If replacing the thermopile doesn t work then you need a new gas valve. Step 1 check for coil burnout.

Locate the front lower access panel to the appliance. Adjust pilot flame as necessary to make sure the thermocouple is getting enough heat.