[VAC] Re: Furnace Trouble

["James Greene" <drgreene@xxxxxxxxxxxxx>]

I don't know anything about the Suburban furnaces with the igniter boards.
However, the earlier models with a pilot light have a so called "air prover"
switch -- a micro contact sail switch that closes to open the main gas valve
when the blower causes it to close the circuit confirming that fresh air is
incoming for combustion and exhaust air is being blown out. If the sail
switch is bad, as it was on the Suburban in my '68 Tradewind, the main gas
valve will not open and the furnace will not produce heat. Air but no heat.

Jim Greene