If I power off unit - reset - let it sit 5/10 mins then power back on.....it works fine again, but for only a day
or two.....I do get 9 blinks (when it fails) which indicates igniter or ground wire.....
The unit is about 5 years old....and only maintenance has been cleaning filter.
check all your grounds in furnace. check from hot to ground and common to ground. If you have more than 10V from common to ground then you have a parts that is shorting to ground internally. ohm out the igniter ... sounds like a nitride igniter and should be between 10 -18 ohms. if everything checks ok... then probably a control board. lets take 1 step at a time though. let us know what you find.
I had a commerical water (elec . ign) last week that had been installed for about 2 yrs. All of a sudden it starting giving problems. I found that durning the install someone forgot to tighten the netural lug in the breaker box . the wire had been arcing inside the box for so long it had almost burnt into