Wiring for new water heater 3 wires to 4 wires?

[Blkbart]

Hello all,
Hoping I can get some advice here. I have a 2003 Itasca Horizon 34HD Just removed my old water heater with 3 wires Brown, Green & Blue coming into it 12V. It does have the motor-aid coolant on it. The newer unit a GCH10A-4E has four wires coming out of it: Green, Blue, Orange & White. The new water heater came with a dual switch, looks though the left toogle is for electric and the switch on the right side is for propane use. Will I need to istall this switch?
Thinking I could use the interior water heater switch. Any suggestions apprecited. The Green coming in from the coach is ground, the Blue and brown must be the 12V feeds from the battery? I have the wiring schematic I pulled off of the internet...
Thanks,
Bart

[creativepart]

Was the previous water heater this one replaces a dual fuel WH - 110v and Propane?

[Morich]

Can you also find the drawings for the old as well as new, so that one could verify the old wiring colors, etc as well as the new and then try to match the use of each wire rather than colors. colors tend to change, so I might have some doubt on connecting them using only colors.

[powercat_ras]

Think you can re-use your current switch and OEM 12 volt wiring, just connect the green wire from the new HWH to chassis ground near the HWH.

Remote gas heat switch to HWH: Orange
Fail to light error light to HWH: Blue
Remote electric heat switch to HWH: White
Connect to chassis ground: Green

[Blkbart]

Thanks for the information and advice. I have decided to mount the new double switch in the water heater housing and wire it to the new schematic included with the instructions.
The original three wires in the plug connect there are three wires. The center one is a ground green, there's a brown one that provides the +12V when the inside rocker is toggled on, the third blue wire has the yellow Itasca wire on the input side of the wire plug disconnect, obviously to feed 12V but no idea what. The newer double switch has a light between the rocker swithes that has a blue wire lead to it, could it be that the original coach blue wire be tied to it also? Perhaps it's for a warning light inside the coach? Hoping to get it figured out. The simpicity of the ground green and the brown toggle 12V is done, just seeking what the blue wire from the original 3 prong feed would hook up to?
Thanks,
Bart

[powercat_ras]

Was the old one a pilot light hot water heater?

If so it might not have had the indicator light the new one with spark ignition has. The old ones are like home hot water heaters and just won't open the gas valve unless the flame sensor is hot.

The new ones don't have any pilot light, they just try to spark ignite the main burner and give up and lock out after 3 tries so they don't release much un-burnt propane if the burner does not light.

The error light comes on if the control board tries to light the burner 3 times and the flame sensor did not indicate flame to the control board. Even though the switch is on it won't try to light the burner again until you toggle the gas heat switch off and back on.

[cbeierl]

This doc Combo 9E-10E Conversion and this old thread Water Heater Wiring may be useful also.

[CharlesMoore]

I agree with powercat_ras that the new water heaters fro Atwood do not have the pilot light ON capability. Call Dometic for the details since they are the ones that designed the new system.
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