Atwood water heater won't shut off

Hey OP......water heater still 'overheating'?

Bedlam wrote:
Verify that your gas valve will actually close. You may have a bigger safety issue going on...

Very easy to do.

Use a long BBQ lighter and see if main flame will light off with WH turned off.

Verify that your gas valve will actually close. You may have a bigger safety issue going on...

Just guessing model?
On the wiring

service manual
Have to ask, thermostat ECO replaced twice- either instance did replacement work?
Positive contact to tank would also be my first verification. If you unplug wire(s) to valve from tstat/eco after it reaches temp(& should shut off) does it?. As you are able to manually turn off, I'm 'guessing' though its not the valve/solenoids sticking once powered on.
As mentioned power has to go thru even if there is another issue. Remove the thermal buttons and test outside. Simple hair dryer would bring to temp pretty quick. Meter to see if continuity breaks (or jury rig as inline switch on low voltage light or something).

Jfet wrote:
That wiring diagram doesn't make complete sense. It looks like both terminals of the gas valve go to the same terminal on the t-stat. How does that work?

RED DC power comes from circuit broad to ECO (high temp t-stat) then thru the ECO to both solenoids on gas valve thru solenoids to ground on black wires.

The RED is power to the gas solenoids. (Black to ground isn't shown)

That wiring diagram doesn't make complete sense. It looks like both terminals of the gas valve go to the same terminal on the t-stat. How does that work?

12V DC power has to go thru both t-stats to get to gas valve......either t-stat opening drops power on gas valve.

Circuit board could be a direct source (circuit shorted) but t-stats still are pathway for DC to gas valve.

Are the t-stats in series with the gas solenoid valve on the water heater burner? If they instead go to a controller board, perhaps the problem is on the board and not with the t-stats.

Should be easy enough to check the t-stats with a multimeter to see if they are opening when at temp.

Gas only with DSI...........

2 t-stats
Normal t-stat preset for 140*F. IF it doesn't OPEN then ECO (High temp) t-stat preset for 180*F.

As a fail safe is the T&P Relief valve set to OPEN and BLOW steam/hot water everywhere at 210*F/150 PSI.

So IF both t-stats are not OPENING and T&P is BLOWING then t-stats are not making contact with clean area on tank wall.


BROWN wires to/from normal and RED wires to/from ECO