Several weeks ago, I awoke to find my 4.5 yr old American Standard oil furnace blowing cold air through the house. Pushing the red reset button on the control unit (Honeywell) restarted the burner. Three weeks later, the same thing happened and pushing the reset button worked again. Three days later, it happened again, but pushing the reset button did not help. The service technician replaced the control unit but the problem persists. The ignition transformer was replaced, but the problem persists. The technician somehow got the furnace working, but overnight (when the thermostat is set down), it failed again. Now the technician is testing the oil pump pressure. He has suggested something is wrong with the oil, although he say the oil looks OK. Is there a way to verify that the replacement control unit is good? Could this be due to a bad high limit switch which, somehow, works when the furnace is on almost all the time but then fails after being off for a few hours? Any advice you can offer will be greatly appreciated. Thanks.

I had an oil fired boiler / air duct system when I first moved into my house.

It was nothing but trouble as it required constant maintenance, as oil is real messy with the inards of these systems, and I got many faults requiring phoning up sevicemen at all hours to get it fixed. It was costing me a fortune in repairs and never reliable.

I would advise you to cut your losses and buy a gas fired system and if possibly dump the duct system as well, that's what I did, as it was very noisy and drafty in some rooms.

You would be better to buy a combined instantainous central heating/hot water boiler feeding a micro bore system of hot water radiators around the house, and gives you instantainious hot water at your taps as well.

A gas system does not require as heavy a maintenance routine as oil, and is far more reliable.

Cheers ColinD