Gas heating stove - will light manually, but not with thermostat

[Mark Sheeler]

I have a gas heating stove that uses a wall thermostat. The stove will not light with the thermostat, but I can push the manual button and it will light. The wires are fine and I put in a new thermostat but it still does not work. I took the thermostat cover off and crossed the two wires, it still will not light. Why will it light when I push the manual button (that the thermostat is wired to) but not from the thermostat? New batteries, new thermostat - no luck.

 

[Lennox65]

I have a gas heating stove that uses a wall thermostat. The stove will not light with the thermostat, but I can push the manual button and it will light. The wires are fine and I put in a new thermostat but it still does not work. I took the thermostat cover off and crossed the two wires, it still will not light. Why will it light when I push the manual button (that the thermostat is wired to) but not from the thermostat? New batteries, new thermostat - no luck.

check the connections of the t-stat wires where they connect to the gas valve. If it won't start when you touch the two t-stat wires together, that indicates that there is a problem with either the wire or the connection at the valve. You may also have reduced thermopile output. There may be enough voltage to work with the short run on the manual switch, but not enough for the longer t-stat run.