Natural Gas Boiler Gas Valve - cmp-h.org.
2011-12-11 · If replacing the thermopile doesn't work, then you need a new gas valve. If the appliance is a boiler or furnace, it'll use 24 VAC to operate the "main" valve. Check to see if you're getting 24 VAC at the terminals on the gas valve. If so, and the boiler or furnace isn't firing up, then you need a new gas valve. Get a Quote