Why does old oil sys. need reset?

[mumichog]

Been living 5 years with 25 yr old oil burner (steam and radiators) on converted coal box from the 20's or 30's. The system has never required anything more than a cleaning to run fine. Before this year's cleaning twice I had to hit the reset button to get the cycle to run all the way up to temp setting and even then was fine for a day or so. two weeks after professional cleaning (nozzle replacemnt, etc), during which it ran fine, now after 6 -20 hours the system won't light without a reset but then runs fine right up to temp. The tech who cleaned the system mentioned that the fuel line was a bit clogged ( but adequate) and the ignition electrodes were near the end of their days but the cast iron boiler was rock solid and gained about 72% efficiency. Well into heat up I occassionally get a delayed igniton and a suppressed 'boom' and get a very little bit of fumes into the house - but always well into or at the end of a prolonged heating cycle, never at the beginning.

Can anyone explain the booming and the back pressure which leads to fumes and the odor of unburned oil to creep into the house? But especially, why does hitting the reset get system to run fine? Why would it run fine after a reset only to not light later in the day?

thanks a bunch!

Freezing My A$$ Off in NH,
Dave

[KField]

It sounds like the symptome of a weak ignition transformer. It will cause all the problems you seem to have and will eventually go completely dead and it will not fire for you at all. There could be other causes but that would be the first to check. You really are beating a dead horse though unless your burner is less than 10 years old, you probably have an energy hog there. 72% is well below the 84% that can be almost guaranteed with todays boilers.

Ken