Lennox G8-137t-1a furnace(1970) - main burner not lighting

Increase your life insurance twofold.

Have your next of kin two counties away with copies of all important papers when you do this.

Wrong move there...

How about you take it out and clean it the correct way?

Replace it if you want, but I dont think that the valve is the problem.

The bleeder tube was not plugged. If it is not the diaphragm valve, what could it be? the pilot light is fine. No gas goes to main burners when stat on. Diaphragm valve is receiving voltage. I assume gas pressure is ok because pilot light and water heater are working. Incidently, how would you clean a bleeder tube?

I posted some pics of the furnace and gas control at the following link:

Looking at those pics, honestly, I would get someone in that either has a tool called the Inspector, or similar. HAve them check the heat exchanger ASAP.

Now, the valves got voltage, but is the voltage completing its trip? Your gas valve is wired through the fan limit switch, and prob at least one overload. Check em. Those valves were rare to go bad, but after 30 years, its possible, but it would be rare.

Ok, I'll get someone to inspect the furnace for safety. What do you mean by completing it's trip? Do you mean that it keeps resetting itself so I don't notice? Because the voltage is 27v continuous. What is the purpose of the fan limit switch? If the fan does not come on in a set time does it shutoff the gas? I bypassed the fan limit switch and still did not get gas to burners. Thanks for indulging me.

it was the gas valve . $436 canadian to fix.