Only the very old furnaces have an ignition system. Now days, they
just pump natural gas into the house, and it never ignites.

Your point about a lockout system is good. Which illustrates that this
poster should call a HVAC company to check the furnace. With it being
an intermittent problem, a clean and check (with emphasis on ignition)
is also a good idea.

--

Christopher A. Young
You can't shout down a troll.
You have to starve them.
..

"jolt" wrote in message
. ..



Does your furnace have some type ignition system.

Furnaces with hot surface or spark ignition prove ignition each time
there
is a call for heat. If for the ignition does not prove within the time
the
board is programed to consider safe (some) boards will lock until the
call
for heat is terminated.