Suburban SF-20 furnace wont stay lit
Over the weekend, I ran the furnace a couple of times. Whenever there was actual combustion, I'd get a pretty good whistling noise. Figured I had some debris in the combustion chamber. Got it h...
Forum Discussion
Old-Biscuit wrote:
Spark electrode must be engulfed in main flame....then the main flame creates a signal thru 'flame ionization' and if spark electrode is good this signal is sent via electrode and high tension wire to control board. This milivolt signals proves main flame and power is keep on gas valve to hold it open.
Spark electrode not engulfed in main flame.......no signal
Bad electrode or high tension wire......no signal
No signal.....gas valve closes
If the furnace worked fine for nearly 6 years, isn't it unlikely that just now the electrode shifted out of the flame path?
