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drifterpilot's avatar
drifterpilot
Explorer
Dec 05, 2018

Atwood Hot Water Heater - No Electrical

My hot water heater is an Atwood 10-gal Model GCH10A-3E. Serial No. 94165016218.
This heater hasn't worked on AC since this past summer. I can manually start it on propane and it runs fine. I started troubleshooting it today and in the process of disconnecting and checking the wire terminal connectors and ground, I found a broken/rusted terminal on the ECO high temp sensor. I went to my local RV parts store and bought the kit containing a new ECO and T-Stat. Neither one of these sensors had been replaced since I bought this coach new. I installed both, filled the tank and it still does not run on AC.
Heater does light off and runs on propane when I manually hit the switch.
I only have access to the front of the heater. I only have a small cubby access to the rear of the unit and I personally cannot fit more than my left arm and shoulder into the area behind the heater.

So, what can I do from the front to troubleshoot the electrical problem?
Can I take an electrical reading at the circuit board?
Can I check anything at the red wires feeding the ECO?
Can I check anything at the brown wires to and from the T-Stat?

Thanks for any assistance
Class A
  • wa8yxm's avatar
    wa8yxm
    Explorer III
    Dec 05, 2018
    What can you do from the "Front".. ALmost nothing

    ON the rear you need a volt meter or better yet a multi meter and you will need a clip ended jumper wire. Insulate also some tape or plastic tubing.

    First turn off the circuit breaker.. Then open the relay box (You may need to cut some tape) and clip the clip lead on one of the wires, black or white, inside.. Now slip the tube over it and clip the other end to the meter probe.. slip the tube over that connection or tape it to insure total insulation.

    Get the other wire (White or black) ready and (Optional 2nd clip lead tube or tape and the other meter lead) meter set for AC volts 150 volt range or higher turn on breaker is power present???? YES good. Try heater does power go away or remain. Remains good

    TUrn beeaker off.. THe element should be under the insulation just above the box (or behind it) CLip onto the element leads.

    Same test only now you should ONLY have power when calling for heat.

    Turn breaker back off and measure element resistance. OPEN CIRCUIT replace element.
  • dougrainer's avatar
    dougrainer
    Nomad
    Dec 05, 2018
    From your description of the access behind the water heater, you will have to PULL the water heater to diag and fix. ANY 120 part or control will require complete removal, even IF you knew that the 120 element is bad(most likely) or the 120 tstat is bad or you have burnt 120 wire connections. Doug
  • Old-Biscuit's avatar
    Old-Biscuit
    Explorer III
    Dec 05, 2018
    rk911 wrote:
    check the thermal cutoff for continuity. the brown wire from the t-stat plugs into one end of the thermal cutoff and the other end plugs into the t-stat connection. if you don't have a meter remove the thermal cutoff and plug the brown wire directly into the t-stat connector and see if the WH works on elec.


    Propane would NOT function if thermal fuse was blown

    OPs version the electric doesn't use the thermal fuse or any component in outside compartment.
  • Old-Biscuit's avatar
    Old-Biscuit
    Explorer III
    Dec 05, 2018
    3E version.....
    Electric is completely separate system
    ALL electrical is on backside
    120V AC T-stat/ECO, element and OEM on/off switch

    NOTE: The ECO (Energy Cut Off---High temp t-stat) if tripped should be a manual reset button in center of ECO.


    Only thing you can check/test is IF the AC circuit Breaker is tripped and if reset it passes AC Voltage

    Every component in the outside compartment is 12V DC for the propane system. Nothing for the 120V AC electric.
  • ggardne2's avatar
    ggardne2
    Explorer
    Dec 05, 2018
    On your model Atwood I believe all the 110V hardware is on the back of the hot water heater (element and thermostat). I am fairly certain the 110V element has its own thermostat and ECO switch similar to a residential hot water heater. The ECO switch and thermostat on the front of the unit only controls the 12V propane side of the heater. Likewise the circuit board is 12V only for the propane side of the heater. Before pulling the water heater out to access the back have you verified that your 110V source into the heater is functioning (110V breaker is on, switch to the electric element is on)? Some heaters have a 12V switch in the RV that fires a solenoid to energize the 110V side of the water heater, if there is not power to the solenoid or the solenoid is bad you will not get 110V power to the water heater.

    Parts Diagram: GCH-10E Parts Diagram
  • rk911's avatar
    rk911
    Explorer
    Dec 05, 2018
    check the thermal cutoff for continuity. the brown wire from the t-stat plugs into one end of the thermal cutoff and the other end plugs into the t-stat connection. if you don't have a meter remove the thermal cutoff and plug the brown wire directly into the t-stat connector and see if the WH works on elec.

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