Need help fast!

Make and model of the water heater, and how /where the solution lies, in one post, newman fulltimer. Thanks In Advance.

It is a diode that goes between the thermastat and the computer

Well now you are out of the dog house then

Thermal link?

Newman thks for helping me fix the heater.. U r awesome..My wife thks u for the hot water!

Your welcome

Newman thk u so much for helping me fix the heater!

He is up and going.He had a bad thermal link to the thermastat

Don't have Atwood info but thinking if red light does not come on, that could mean no DC current or else the thermostat is telling it that the water is already hot. Your water is cold. (You can check the outside relief valve to see if it is under pressure with hot water but for some reason you have shut off the hot water supply to the hot water line with the by-pass and it is only getting cold water in the hot line.)

On the Suburban there is a reset button for the high limit on the thermostat so you'd think there is one somewhere on an Atwood.

Sounds like the start of a PITA but could get out the voltmeter and see if there is any DC on Both sides of the switch/light set-up when it is in the on position.

You must have a atwood then check the fuse on the black box on the outside part of the unit upper right corner the fuse is in the upper left corner of the box.
Also check the thermal saftey switch
I will send you a pm