11-29-2016, 07:42 AM
Brad: it sure is a pain to get at these furnaces.
If it ignites and then shuts down quite quickly I would suspect the flame detector as it is the first thing the board checks following ignition. It wants to ensure that you aren't filling the furnace with propane that should it subsequently ignite might blow the furnace apart.
I can't recall exactly how accessible everything is. If possible check that the flame detector is working by measuring voltage at the control card. If that isn't possible I would suggest pulling the furnace and cleaning the wiring connections at the detector and at the control board. If that fails to correct your problem I'm guessing you will need a new either a new detector or a new control board. Many RV dealers have the ability to test the board and if you have it out it might be worthwhile having tested just for assurance. For the 77 coach I used to have replacement boards were available.
In summary: I think the flame detector signal isn't being received by the control board and that it is likely the spade connectors at the detector have high resistance. The flame detectors are still working in the 77 coach as far as I know so I'm inclined to think yours are too.
I hope this helps
If it ignites and then shuts down quite quickly I would suspect the flame detector as it is the first thing the board checks following ignition. It wants to ensure that you aren't filling the furnace with propane that should it subsequently ignite might blow the furnace apart.
I can't recall exactly how accessible everything is. If possible check that the flame detector is working by measuring voltage at the control card. If that isn't possible I would suggest pulling the furnace and cleaning the wiring connections at the detector and at the control board. If that fails to correct your problem I'm guessing you will need a new either a new detector or a new control board. Many RV dealers have the ability to test the board and if you have it out it might be worthwhile having tested just for assurance. For the 77 coach I used to have replacement boards were available.
In summary: I think the flame detector signal isn't being received by the control board and that it is likely the spade connectors at the detector have high resistance. The flame detectors are still working in the 77 coach as far as I know so I'm inclined to think yours are too.
I hope this helps
Jon Kabbe
1993 coach 337 with Civic towed