The Atwood water heater I’m installing is a dual heat unit. It heats from propane and also with a 110 VAC heating element. Atwood provides a dual panel switch that also includes a pilot out indicator lamp. The dual switches allow you to turn on gas heating, electric heating, or both. The nice thing about being able to use both heat sources is that the hot water recovery time is greatly increased.

Here is the switch that Atwood provides.

Atwood Dual Switch

Since I’m replacing a water heater and not putting one in from scratch, I decided to reuse the switch panels that I had already in my trailer. The tank level gauge that I have is a SeeLevel by RV Gauge. The SeeLevel has switches built in for a water pump, and water heater.

SeeLevel

The panel is mounted on the opposite side of the trailer from the water heater. Since its a long wire run, I used a relay to power the water heater which is controlled by the panel switch. A relay is basically a remotely controlled switch. Doing it this way allows relatively small control wire from the switch to power a heavier duty appliance like the water heater.

The SeeLevel only has one switch for the gas heater so I had to add a second switch for the electric function that the Atwood panel provided.

New Switch

Control relays. Left controls the gas function. Right controls the electric.

The other nice thing about the SeeLevel panel is that it provides for a Pilot Out lamp. This will light up if the water heater fails to ignite the pilot after three tries, like if you run out of propane. This way you know something went wrong and you can check it out.

There does seem to be some kind of bug, or maybe its the way they meant it to work. If both the gas and electric switches are on and the heater fails to light, the Pilot Out Lamp will not turn on. It will only turn on if the electric switch is off.

I tested this by leaving the gas off and turning on the heater.

Pilot Out Indicator

So after dressing the wires a bit more, I needed to add some more bed support. Here is a photo of the end result.

Completed installation

Interesting side note. If you look closely you can see two pipes leaving the back of the water heater. The way I understand it is that if this was installed in a motorhome, you could plumb the coolant through these which would keep the water heated while driving to you next spot. Kinda cool.

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