Hi All,
I have a convection fan blower issue on my 2008 Mt Vernon. The stove ran all last winter (purchased used last fall) and sat all summer, I fired it up three weeks ago and it was running fine until one night it smelled a little warm and then I got a drop tube max temp error. I reset the stove a few times before realizing that the convection fan was not turning on to push the heat out, and the drop tube was heating up because of that. I removed the fan, rigged up a flexible duct to a small external fan, dropped flame height to -5 and found that the stove would run fine in that configuration so I could troubleshoot the fan and system. I removed ring TC on drop tube, sanded mating surfaces, tested TC with a millivolt meter and a lighter and I was able to observe a rise in millivolts with heat but didn’t get any great consistent readings (its a low quality meter with a millivolt setting).
I removed the overheat snap disc and cleaned mating surfaces, and checked it over a flame with an ohmmeter and it has continuity, but I also found that even once it snapped it still had continuity.
I removed the control board to inspect/clean and in the process broke a pin off TC1 for firepot TC and had to solder in a new pin.
I cleaned out the fan, tested the wiring harness from end to end, took apart the fan and plugged the harness in and tested continuity from end of harness to solder points on fan motor.
I purchased a new fan and plugged it in, got the stove up to temp with flame height at -3, used an infrared thermometer to make sure drop tube temp was well above 105 degrees and still nothing. With drop tube temp well above 105 degrees I removed the fan wiring harness from the control board and got very low voltage numbers. I’ll attach video below of what I got for voltage readings. I also retested the drop tube thermocouple tonight with the stove heated up rather than using a lighter and couldn’t get a decent reading at all, I plan to pick up another meter tomorrow to double check.
I’m at the end of my knowledge here, could it be as simple as a Drop Tube TC that’s not getting the right millivoltage? Wouldn’t the unit not run at all with a bad drop tube TC?
Thanks in advance,
Zak
I have a convection fan blower issue on my 2008 Mt Vernon. The stove ran all last winter (purchased used last fall) and sat all summer, I fired it up three weeks ago and it was running fine until one night it smelled a little warm and then I got a drop tube max temp error. I reset the stove a few times before realizing that the convection fan was not turning on to push the heat out, and the drop tube was heating up because of that. I removed the fan, rigged up a flexible duct to a small external fan, dropped flame height to -5 and found that the stove would run fine in that configuration so I could troubleshoot the fan and system. I removed ring TC on drop tube, sanded mating surfaces, tested TC with a millivolt meter and a lighter and I was able to observe a rise in millivolts with heat but didn’t get any great consistent readings (its a low quality meter with a millivolt setting).
I removed the overheat snap disc and cleaned mating surfaces, and checked it over a flame with an ohmmeter and it has continuity, but I also found that even once it snapped it still had continuity.
I removed the control board to inspect/clean and in the process broke a pin off TC1 for firepot TC and had to solder in a new pin.
I cleaned out the fan, tested the wiring harness from end to end, took apart the fan and plugged the harness in and tested continuity from end of harness to solder points on fan motor.
I purchased a new fan and plugged it in, got the stove up to temp with flame height at -3, used an infrared thermometer to make sure drop tube temp was well above 105 degrees and still nothing. With drop tube temp well above 105 degrees I removed the fan wiring harness from the control board and got very low voltage numbers. I’ll attach video below of what I got for voltage readings. I also retested the drop tube thermocouple tonight with the stove heated up rather than using a lighter and couldn’t get a decent reading at all, I plan to pick up another meter tomorrow to double check.
I’m at the end of my knowledge here, could it be as simple as a Drop Tube TC that’s not getting the right millivoltage? Wouldn’t the unit not run at all with a bad drop tube TC?
Thanks in advance,
Zak
