Atwood Water Heater gas comes on-only electric switch is on

STBRetired wrote:
Before you install the board, you might want to make sure that the white and orange wires are not shorted together somewhere between the switches and the control board.

Just put a meter on them and make sure there's no continuity?

On ours, it is confusing or was. When the switch glows orange there is a fault. It's an Atwood.
We replaced or had replaced both high and low temp thermostats, not adjustable on ours, but understand some models were/are.
The heating element could be bad too or instead. I don't remember if we replaced it but not a bad idea since doing the thermostats too.
We always run both electric and propane at the same time, for high recovery rate.
The next year model of water heater was either electric or propane but not both
Right before time the light was glowing, I suppose since it is in a a cabinet, out of view, we got spurts of very high temp water then cold warm and not enough for a shower and then cold.
* if the light is glowing the wire is not broken.*
The two switches cost us $28.00 to be installed, I think. They don't cost much obviously. Just unscrew them with wrench from the tank, with heaters off and water drained and reattach wires and so forth. First real problems with water heater since new 14 years ago. A general cleaning and diaeletric compound on the electric plugins and such with a cleaning hopefully at least 14 more trouble free years. We do filter every ounce of water into the coach.

Wonder if the board got wet during the flush? Might dry out and be ok.

pappy43756 wrote:
Wonder if the board got wet during the flush? Might dry out and be ok.

Might have but..I suppose every time we've flushed ours it might have gotten a few drops but it is out of the way of the drain, mostly and encapsulated in plastic or epoxy.
Wires get kinda grungy if unit is not cleaned and where they plug together might have gotten damp. there is one wire that has a looser than I like plastic tubing over plug to thermostat, I think.

nazpaz wrote:

STBRetired wrote:
Before you install the board, you might want to make sure that the white and orange wires are not shorted together somewhere between the switches and the control board.

Just put a meter on them and make sure there's no continuity?

Yes, just disconnect both ends and put a meter between them to check for continuity. When I worked HVAC, I saw that in a S&B. Someone hung a picture and put the nail into the thermostat wire. Furnace ran continuously. Could be possible abrasion somewhere in the run of the wiring. Best to check before an unnecessary board replacement.

Continuity testing......

Orange wire (gas operation) and White wire (electric operation) are in the water heater outside compartment.

Wires go to backside of WH Tank where RV MFG connects wires that come from INSIDE the RV where ever the on/off switches are installed

LONG test wires required.
OR tone generator

Old-Biscuit wrote:
Continuity testing......

Orange wire (gas operation) and White wire (electric operation) are in the water heater outside compartment.

Wires go to backside of WH Tank where RV MFG connects wires that come from INSIDE the RV where ever the on/off switches are installed

LONG test wires required.
OR tone generator

Thanks - I doubt that I'll be doing that unless the new board has problems. I will get it in a few days.

Check was to see if there was continuity between orange and white, not to check for continuity from switch to board. Another easy way to check would be to remove orange wire from board, turn on electric switch and check to see if 12V on orange wire.

STBRetired wrote:
Check was to see if there was continuity between orange and white, not to check for continuity from switch to board. Another easy way to check would be to remove orange wire from board, turn on electric switch and check to see if 12V on orange wire.

White (electric) and Orange (gas) wires are in same multipin connector
Could pull connector off board and check for continuity between White and Orage wire PINS

Could even turn either on/off switch on and check for DC Voltage between the 2 PINS (with connector pulled off board)

Good idea!

post deleted