We have an oil fired boiler that started to cut out a couple of years ago, and was eventually fixed by replacing the control box (Honeywell TF832 3). The same thing started to happen a few weeks ago, so I bought a new control box, plugged it in and fixed it - temporarily. Sometimes it runs fine for days, then is a bugger to get going. Tonight, I removed the control box, sprayed contact cleaner (Servisol Aero Klene
50) all over the contacts within the boiler, replaced the control box, and it is running.Coincidence, or could the problem be nothing more than dirty/corroded contacts that are temporarily cleaned whenever a control box is unplugged/plugged in?