M41 fan issue

[ERB]

I have a Monitor M41 that I am trying to get a couple more years out of. I have been able to maintain/refurbish it over the years with help from this forum and it owes me nothing. I came home the other day and the heater was on but the fan wasn't running. I shut the monitor off. The fan then turned on during the cool down cycle. I have tried turning it on multiple times and the same thing happens every time. The fan does not turn on while heating but does during the cool down cycle.

I do have a local shop that services Monitors. It is $80 just to get it on the bench to diagnose it. Is this something that I could possibly diagnose and fix myself ? Is it worth getting it diagnosed by a professional? Or has it finally reached it's end of life?

[hawkins111]

Which fan are you talking about? The combustion fan or the circulating fan (on the back of heater).

[ERB]

I am taking about what I believe is the circulating fan. It is the one that you can see externally in the back behind the burner. It has a wire grate over it.

[hawkins111]

The circulating fan takes a while to come on at the beginning of the cycle and goes on for a while after the unit cycles off or you turn the unit Off. That is normal. The circulating fan does not come on right away when you turn the heater On.

We need to see just what your Burner Statue lights are doing at the beginning of the cycle. When you turn the heater on and the room temp is below the set temp the heater should start its cycle. The combustion fan should come on. It will run for three minutes or so before the Burner Status lights come on. When the Burner Status lights come on, the fuel pump is On. You should hear and see a flame in the window. Two minutes or so later the circulating fan should come on and heat should come out the front. Shortly after the Status Lights come on Low/Med and the Circulating fan starts and the Status Lights may go to Med/ High. The Circulating fan should step up its pace to High. The unit will heat the room up and settle down to Low. When the room is 4 degrees over the set temp the unit will shut off and the circulating fan will continue for three minutes or so and go Off. That cycle happens every time the heater starts and stops.

Try to start your heater with a timer handy and see what happens at what time.

[ERB]

Ok, I finally had a chance to test the timing of my heater. Short answer is that it started up an d functioned norm daily. It has been running for about 20 min now.

I had checked it two or three last week and every time the burner turned on and ran without the circulating fan. I had it on for 10+ min each time.

I guess I'll keep an eye on it for now and see how it goes. Hopefully there are no other issues.

Thank you for taking the time to answer my questions. I will follow up if it acts up again.