Atwood 10 Gallon Water Heater

It may be a couple of things
1. Is your water heater in bypass mode? If so take off bypass.
2. Some water heaters have a safety switch on the water heater itself. Check to see that the switch is in the On position.

You said you turned on the "electric" switch....are you hooked up to electricity?

More than likely, there is a switch directly on the water heater, accessed from the outside of the camper. Remove the cover and look for a little rocker arm type switch. I think almost all water heaters are double switched: the switch on the wall inside your camper, and the switch on the outside of the water heater. They both need to be turned on. It's a safety feature to keep someone from flipping on the water heater inside the camper when there is no water in it.

The knob can point to "water on" or "hot water bypass" it is turned to "water on". Yes, air conditioners and appliances all running correctly on 50 amp hookup.

Ok, so when the switch is on inside the rv, I can hear a squealing or high pitched noise coming from heater when I go out there to look at it. But cannot hear it when switch is off.

We have looked everywhere for a second switch. We have hot water on propane. I will call our dealer on Monday. Thank you everyone for your help!

This is exactly what mistake I made when we got our first trailer and when I didn't understand how it all worked.
Couldn't figure out why the water heater would not work on electric. I was not plugged into shore power...I thought it would work off the battery. Neighbor came over and set me straight.

Based on the information you've given us so far, indicates a electrical issue. The red light inside is a system failure issue. Possibly a control board failure. The thing that puzzles me is the high pitch noise you are hearing at the WH when the electric is on. Can you determine the area where the noise is emitting from? Please keep us updated. Thanks, rockin'

Atwood doees NOT use the switch in outside compartment..........only Suburban does

Works on LP but not on electric.
LP and Electric use SAME DC controls, t-stats etc.

Red Light ON (fault light) only comes on when using electric when the ECO (high temp t-stat) opens
That means it sensed high temps of 180*F OR the wire connections on ECO are not making good contact.

So IF you have water in water heater and red light is on when you turn electric switch on then in outside compartment unplug, clean & replug wire spade connectors on ECO

Due to same t-stats/controls being used for both LP and Electric a milvolt current must go from circuit board to ECO on RED wire and the to gas control so that the ECO is a functioning part of controls (HI temp cutout backing up normal temp t-stat).
Doesn't take much resistance to stop milivolt current from flowing.
Circuit board not sensing ECO in circuit---Fault light ON (Red light at on/off panel)

I will check those connectors for sure. Headed to laundry and then will be back. Thank goodness for the propane. Our first night in it and didn't want momma to take a cold shower. Yikes! I will update you later.