All quiet with the oil furnace

Hello! Residence purchased 2 years ago with Carrier 58CLR + Riello 40 oil furnace from 2001. Oil furnace has run well for past two winters up until last week. Scheduled yearly maintenance is set for late April but is currently not turning on. I have checked the blower capacitor, hit the reset button, check for 120v, cleaned the photo eye in Riello, checked the filters and no fuses blown. The electronic thermostat has batteries and is lit but receives no response from the furnace nor can I turn on the fan manually from the thermostat.The unit will not turn on and because of a history of fan board replacements in 2004 and 2007 I am asking the forum whether they recommend spending $85 to buy a new fan board as the first step in resolving my problem of no start, no noise , no blower.

ps: not sure whether its related or not but received an oil fill up a few days prior to the problem

 

Welcome to the forums.

Doesn't that unit have a low speed blower switch on it..... is that working ?
I would check for 24vac at the control board.

 

There is a transformer to the left of the fan control board that can be replaced inexpensively and easily. It is responsible to convert 120V going in to 24V out. I was not able to detect voltage at the 120v terminals(2)or the 24V terminals(2). I can confirm that the source of the 120v does reach a junction box for the furnace but the green and red wires leaving the junction box do not have detectable power. I am at a loss how the transformer or fan board gets energized to start the furnace.

 

You need to trace the wiring to the transformer. Without the 24vac, I'm pretty sure, the control board won't operate. A green wire usually signifies a ground wire. You'd need to find maybe a white with that red.

If you have a service switch on the furnace or maybe a second one in a different area.... you'd need to make sure they were ok and allowing 120vac to get to the furnace.

 

Thanks! I will perform those tasks and post what I discover. HVAC tech performing warranty work on another residence stated the same suggestion. He stated the service switch may have failed and to check the voltage from the switch.

 

Well tonight when I went to check the voltage at the service switch on the furnace I followed the electrical wires from that service box up towards the upper floor joists which led to another service switch at the top of the stairs. One of the tenants had turned that service box OFF!!! Problem solved and oil furnace is making heat again. Put a big sign next to the switch not to touch unless an emergency. Thank you for guiding me in the right direction. I am a proud member of this forum!