Heyyy.... I said I'd clean up the wiring! LMAO. It was a whole bunch of fun.
I gave thought to a pilot light idea, but, a propane pilot wouldn't stay lit and an electric arc would be difficult to house in the burn chamber & not melt as well as be expensive to run. Even propane would cost $20 a month to keep going. I do think the best way it as I'm trying....disrupt the mixture before a flame tickles it to ignition.
I hae not had a puff back since day two. But, I think I'd gain .001% efficiency by closing the 5/8" hole.
The anti-boom cover plates are right next to the clap-on switches at Bangor Hardware.
I think one more delay timer...break the wire going to the 120V relay duing the 10 seconds, yaaaaa, that'll do it!
You should see it work! It makes a Bzzzzzz, but holds the door open just right. *smile* No flak jacket required, just safetly glasses, a GFI circuit & a good ground wire.