Welcome! Here are the website rules, as well as some tips for using this forum.
60 yr old Burnham Pace Pak Oil-Fired Boiler still in operation BUT...
I am writing for my 88 yr old dad looking for advice. This Burnham Pace Pak Oil-Fired Boiler has a Burnham Burner Model 551. All original to the 1958 farm-house. Original T-stat too. Has worked very well for 60 yrs mainly as backup to the normal mode of wood heat since plenty of trees on the farm. Only real repair was 30+ years ago; A new ignition transformer. We are 99% sure it was a Dongan because he has an exact replica given to him about 35 years ago.
Here is the odd thing. Dad is now forced to operate the system manually by a wall switch. The system will start fine in the morning IF the water temp is below 100 degrees. System will get the house nice and warm via its hot water baseboards. He will shut it off but the system will fire until the water temp gets below 100 (basically its waiting till next morning). When he tests it to see if it will fire at higher (tahn 100) water temps, it will not fire but WILL continue to spray fuel into the burner box!
Dad and Mom (89) found this all out a scary way when operating normally off the thermostat. Thermostat was calling for heat but it was (apparently) only spraying fuel into the burner box for a long time. Then the electrodes must have sparked "at will". It made for a "boom" sound, rattled the utility room door and sent soot onto window sills. That prompted immediate switch to manual mode.
We are Richmond VA area. Besides the ongoing talk to get a whole new system (no natural gas near), we welcome your thoughts to limp home till spring and summer. Swap the transformer? If yes, that Dongan transformer has two lead wires that attach to the two electrodes which are cast into the porcelain shouldered piece (that fits in a bottom hinge plate). Does it matter which wire goes to which? Same question for the two (only) black wires that go to the electrical j-box.
I am just a dumb architect and out of my league here. When born during the 1929 Depression it makes people want to fix their things whenever possible. A coloring book, crayons and fruit was an awesome Christmas growing up he says. Thanks!