[Kthomase7]

Does anyone have any idea about this thermostat that also has a square button on the left?!

[PlazaGuy]

That is the 220 High Limit Switch for the Electric part of the Aqua Hot. If you press down on the red button, that will reset and you will have electric 220 heating.  If it will not go down and stay down, you have about a $450 problem! Been there down that!

[Kthomase7]

Isn’t the left side diesel and the right side electric?!  I know the obvious red button on the lower right side but I’ve also just been told that the button on the lower left thermostat is the old style with the subdued red button.  That’s a very expensive thermostat!  I just replaced my control box 3 days ago! $$$$$

[Fulltiming]

The insulation on the white wire crossing that thermostat is certainly not looking good Keith. I would be concerned about the long term integrity of that wire.

[Kthomase7]

Hi Michael!

Yes I thought the same thing but it seems to be some sort of residue on it along with a few other wires on top of the unit! I’ll dive deeper into looking at the culprit of the residue and check the integrity of the wires!

Thanks Michael!

[Kthomase7]

Sorry for the confusion but I meant the diesel side thermostat has a reset button as well as the electric side! My description of left side was the diesel side!
Thanks for the responses!