Quote:
Originally Posted by Skip426
I don't believe this furnace uses a thermal couple ; as such. The igniter probe and wire serves a dual purpose , delivers the spark then detects heat and reports to the control board.
I helped with a similar problem , and the flame diffuser had rusted out and wasn't directing the flame back at the probe.
Before you remove and look at the diffuser , I'd try swapping the control boards between the two furnaces , to confirm they're good.
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Ok...going through the systems as a finial check before I leave.
The rear furnace will fire up and shut off three times and then just the fan runs.
I'm assuming it is a thermocouple problem (flame comes on, heat comes out the exhaust (not plugged with wasp nests)).
The rear furnace has been questionable in the past.
Interestingly the thermocouple is not picturered in the manual.
It is a Atwood Excalibur 8500 Series III
The front one works fine so we are good for this trip as only the evenings will be cool (50 degrees).
Has anyone removed one of these units from their coaches?
Anyone replaced the thermocouple in one of these? Part Number?
Here are my two units, with the covers removed.
Looking closer I found some mounting screws for the face plate that surrounds the furnaces.
Evidence that someone has been here before is visible, and I know who. Back when I was trying to be lazy and have work done for me I had Caledonia RV replace the blower motor in the front furnace because it was squealing. I now know that it was most likely not the blower motor but a misalignment of the squire cage fan blades.
Note the missing screws in the above picture and the screw in this picture that is in crooked. The only way that screw could be like that is if it was in the hole when the face plate was put back, because you cannot get a screw driver on the head of the screw. They were just to lazy to remove the face plate and install the screw correctly
I found two more screws up inside the compartment lip. This one is stripped out and is above the left furnace and will be a real pain to get out.
In addition there are screws through the floors of the furnaces and into the face plate. This is the rear furnace floor which is undisturbed.
This is the front one and the screws were replaced with screws with heads.
I have decided to stop at this point because I can see this developing into another project. The front furnace will be fine for this trip.
It has been suggested that "I don't believe this furnace uses a thermal couple ; as such. The ignition probe and wire serves a dual purpose , delivers the spark then detects heat and reports to the control board."
So until I know more this project is on hold.
Any input?