Something I noticed right away and just now am going to mention, since no one yet has mentioned, is I don't like the looks of the resistor located on lower left temp switch.
Sure looks to have cooked the insulation on the coiled wire there. If so, that would be the bigger concern at this point.
Yes, McGiever - you're onto something there....
After chatting with rockwood this afternoon, I believe that some portion of that limit switch is faulty; here's what we were able to determine:
First off, the wall thermo switch has full voltage (120v). This runs to the same switch that is controlled by the hold fire unit; when the wall thermostat is turned up (thereby calling for heat), this tells the auger/comb fan to get busy. What we noticed is that once the stove was burning away, the stove would shut down, and be unresponsive when the thermo was turned up. HOWEVER - once I manually turned on the circulation fan for just a few minutes, the stove would cool enough to allow the thermo's demand for heat to kick on the auger/comb fan. Does that make sense?
The unresponsive limit switch is not calling for the circulation fan when it should (which cools the stove) - which makes the stove stop burning too early, which leaves the firebox full of half/poorly-burned coal....and that's where we came in on this whole show. We've now come full circle. It was the faulty main power switch that got me there, but once that was repaired, we've discovered the faulty limit switch, which is/has been causing the entire mess that began the owner's complaining. Phew - we took the long way around....but we got there.
Now - I'll make a few phone calls tomorrow and see if we can chase down a replacement switch. McGiever - you've definitely identified something sketchy in that coil/limit switch. Hopefully we can find a suitable replacement relatively soon and get this thing back to 100% functionality.
Monster big thanks to rockwood for his help this afternoon. If everyone else on this forum site knows what heh knows, then there's a WEALTH of information to be tapped into around this place!
I'll keep you all posted on what I find this...