Monitor 441 Heater

[FordMan59]

Not sure what your problem is, but I'd be concerned that it may have taken a lightning strike and fried the main circuit board. I had a neighbor have a Monitor hit by lightning years ago. He said it cost several hundred dollars to have it repaired. Since then I always unplug mine when a thunderstorm rolls through and also unplug it every spring and leave it unplugged until fall of the year when it's needed again. We've had to unplug our heater both of the last two nights in the middle of the night, because of strong thunderstorms with heavy lightning in the area. Surge protectors often don't protect equipment plugged into them very well. I had lightning ruin a printer and computer monitor several years ago after a lightning strike and both were supposed to be protected by a surge protector. I have the Monitor service manual in PDF format and will send you a copy if you'd like, it might help you find your problem. If you want a copy send me your email address in a PM and I'll get it to you asap. If you need to have the board repaired the following link will take you to a company that repairs them. http://www.heaterpcbrepair.com/

[HayZee518]

judging from your responses lack of fuel is not a problem. that brings us to the air flow stream or the safety devices. The flamerod is the first that comes to mind. when the unit is running its approx position is halfway between the combustion pot and the combustion ring. If when it is heating up if it ever touches the ring or the pot, the unit will shutdown and lockout. Mere shutting off the unit with the on-off button isn't enough to reset the computer. you need to unplug the unit and plug it back in. 24 volts is applied to all boards when the unit is plugged in.
The next to check is the safety chain devices. overheat klixons, high plenum klixons, airflow proving switch, low fuel cutoff in sump. These are all in series connected.