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Bard oil furnace, F97, new nozzle & filter. however, has had 3 ignition transformers in the last 20 years. It quits, when I hit the reset, sounds like an arcing noise, I remove the transformer, clean the flame detector lense, which looks good, reinstall it, & it fires up, works good for a day, then quits.
I am ordering a new transformer to be sure, does this carry dangerous voltage after the power is shut off?
(Also ordering new flame detector to be sure) Bob

checkin

Update: It turns out the Burner Primary Control was bad, (668-401) was replaced with a Honeywell photo primarz ($140). The new unit is sealed, the old one comes apart with one screw on housing, visually inspected, the reset button housing is transparent acrylic, can see thru to reset button components, looks like the contact points were carboned up, (20 yrs old) and/or there is a resistor in there that looks fryed.
My theory is the contact points of the reset was the first main problem, which explains how I got it to run for 3 more days, just by shutting off the power, then turning back on. After doing this a few more time when it quit running, it loaded the resistor down & fryed it, am going to take apart later, & see exactly what then update if I find anything to the contrary.
Cannot dissasemble the reset housing, but am wondering if in a pinch, you could carefully drill a hole large enough to access contact points with small file or sandpaper, seal hole, & fire up until new part is ordered.

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The burner control box is the grey 3x4" box sitting to the right of the ignition module with four screws (2 to the thermostat).
The initial symptom to this was a buzzing sound & no ignition to the furnace, if you put your ear close down, you could detect a small ticking sound, or arcing of the contact points trying to connect.