Greetings from the Sunshine Coast, Larry Cavens here the RV Doctor
well first things first here, at the switch for a combination unit you should have two switches with a red light between them white in color. The left one should control the
electric operation the right switch should control the gas operation, Or if you have just a single switch with a red light beside it should be a color black. Now there's another configuration where some of these Winnebago's will put the switch in the over the range with all the others in this case it should be a single switch with the word check or the word pilot out above or beside it. Now when you turn on the unit the red light should come first for two to three seconds
indicating that the system is running, if the burner fails to light the red light should come on again and remain on until you reset the unit by turning the switch off then on again. I had the same experience and what solved my problem was two things/ 1st depending on the age of the D S I board it sounds like it's been subject to either a power brown out or a power spike or an AC ripple which would hamper the microcircuits and its now operating on a backup or in limp mode where manual operation is possible, in that case you must replace the board / 2nd the power converter itself could also be damaged as well and its not putting out the required voltage which should be at 13.5 DC maximum no higher and the storage battery is not filtering the power circuit, if this is the case this would indicate the power converter is putting out raw power and the sensitive circuits in these D S I boards are subject to fail, this will include your furnace and your fridge as well, another possibility is that the storage batteries have been charged by a external battery charger while still hooked up to the coach that in itself will ruin the charging circuit in the converter and the rectifying circuits in the D S I boards,
so if it were me first I would replace the board on the H W Heater and secondly get the converter inspected for the power output and the purity of the
DC wave form as it should not have any AC ripple in its wave form . hope this helps ya. You can Email me at
[email protected] and let me know if I can be of further assistance.