Wiring Instructions For A Dometic RV Water Heater Single-Panel Control Switch

Updated 05/26/2026 | Published 11/20/2021

Question:

Hooked the three wires up in back but I have none of the other wires hooked up old one didnt have but 3 wires

asked by: Johnathan H

Expert Reply:

Since you don't have the wiring harness on your previous RV water heater you most likely had an all propane powered unit. The Atwood RV Water Heater w/ Heat Exchange - Gas and Electric - Automatic Pilot - 8,800 Btu - 6 Gal #AT96163 is powered by both gas and electric and has a wall mounted control switch which is where the red, blue, white, and green wires on top of your water heater would run to. Since you don't already have the # AT91859 wall switch installed you would need to install it in your RV and run wires from it to the water heater. I've attached the wiring diagram for you below.

Depending on the distance of the switch to the water heater you could use the Replacement 4-Wire Control Harness for Atwood Water Heaters # AT93312 which will come with connectors to easily attach to the prongs of the # AT91859.

expert reply by: Kevin C

Wiring Diagram
(click to enlarge)

Lisa

5/16/2025

I've got brown wire coming from bottom back side rv water heater replacing cause got some bad breaks in the wiring but trying to figure where it's coming from and where it's gotta hook up at and have this component with 1234 on back of it with looks like 2 D batteries

Robin H.

5/20/2025

@Lisa what kind of water heater is it? What is the problem?

Lisa

5/16/2025

There is 2 switches one inside on wall and 1 inside the compartment with outside vent and thermostate and reset switches I'm not to familiar with this setup never lived in RV before

Warren

10/14/2025

When I went to change out the hot water heater, I undid the 2 wires for the hot shot on the thermostat stuck on the tank then I pushed the hot water heater out, not knowing the blue, green and brown wires were on the side, ripping them out. They come up out of the cabinet floor. The brown one ripped completely out. What are they hooked up to? I have the converter and water control panel pulled out and am not seeing where they go.

Jameson C.

10/14/2025

@Warren If you use the above diagram you can see where each of the wire colors are supposed to go. It looks like its the wires that run to the remote switch.

Bill W.

5/22/2026

@JamesonC I replacied my propane only water heater with a Dometic WH-6GA water heater and the schematic that came with it was for an electric/gas option and it was a little confusing. It has two plugs and the gas only has one 3 conductor plug, (blue, green and brown). The blue goes to the fault light, the green is a ground and the brown is the +12vdc from the water heater on/off switch. I also tapped into the power out side of the switch with a light to show when the water heater is on. (I grabbed a ground for the light near the switch). This stopped me from accidently leaving the water heater on when traveling. I hope this helps.