Sofie's Folks wrote:
Our 2022 dual-heat WH-6GEA water heater quit working midway thru our second outing of the season. There is no firing under gas-mode, nor heating under electric-mode. The OM speaks of a red fault indicator light but I find none on the until or the central control panel. I expected a reset button but there doesn't appear to be one. Service Departments are booked for +3 months now. Any troubleshooting tips for a semi-capable RV owner suggested?
2022 JayCo Whitehawk 30Z
The part number you listed points to the new style Dometic water heater. They still use the older style control board.
First off, the red fault light which is normally inside on a tank panel next to the gas mode switch, is only for a LP gas mode ignition fault. There is no fault light for the electric mode. The DSI fault (direct spark ignition) means on gas mode, the flame did not start when it was supposed to, or the flame went out once started when it was not supposed to. There is no reset button, you turn the heater off, then back on and it resets the fault.
Since you have no electric and no gas mode working, it could be a few things. Here is a quick way to help narrow things down.
Put the system in LP gas mode, have 12 volt power on naturally, and turn on the heater. Listen for a clunk (the gas valve opening)
and click click click the igniter sparking. It will take a few seconds after you turn it on, but if there is no clunk and no click click click, then it can point to these simpler things first.
The safeties are not made. There is a thermal fuse in series with the main T stat. On older models, corrosion on the terminals of the any of the safety circuit connections prevents that circuit from making and it will not allow either the gas mode or electric mode to start. Many times, unplugging and re-plugging breaks up the corrosion and the circuit then makes.
There is also the connections on the main control board that corrosion or a loose connection goofs up the circuit connections. Same thing here, unplug and re-plug and try again.
Clean up any corrosion if you see it. Loose connections act like corrosion, the circuit does not make.
If you still have no clicks and clunks when starting on LP gas mode, then it's time to break out a 12 VDC meter and see if 12 VDC is going to the heater. While the electric element needs 120 VAC, the rest of the heater all works on 12 VDC and LP gas. So you can use the gas mode to test out the controls for both electric mode or gas mode to see of the safety circuit is working, but if you have no 12 volts going to the heater, nothing will work, the same if the safety circuit above does not make.
Since you camper is new, it does not mean corrosion or a loose connection is not in play. There is also a small fuse on the control board, it should not be blown, but check it.
If you have 12 VDC going to the heater control board, you checked the connections for being loose or corrosion, you might have the T stat, the thermal fuse not making the circuit. It is a normally closed circuit and doing a continuity check can prove it out. To check it, turn the 12 volt power off, unplug the wiring on the safety circuit from the main control board. The wiring from the control board and back to the control board and do a continuity check on those two wire would prove out the circuit is made or not. If it is not, then figure out what is breaking the circuit. This takes a little more skill with an ohm meter, but it is basic control troubleshooting. Or you have a bad control board.
Hope this helps
John
2005 Ford F350 Super Duty, 4x4; 6.8L V10 with 4.10 RA, 21,000 GCWR, 11,000 GVWR, upgraded 2 1/2" Towbeast Receiver. Hitched with a 1,700# Reese HP WD, HP Dual Cam to a 2004 Sunline Solaris T310R travel trailer.
