New water heater wiring

[Eddy W]

I have a 2003 Adventurer on a workhorse chassis and have to replace my water heater and the new one is a 4E instead of a 3E. It has a relay and different wiring than the old one. Does anyone have tips or hints to wire it so we can still use the old internal monitor panel switches or do we have to use the new one and mount yet more wiring inside the H/H

[AFChap]

The 4e is switched on 12v rather than 120v as the 3e was. My coach came with an electric 12v winterizing valve mounted by the water heater. I had replaced it with a manual valve under warranty when dealers could not make it work properly. I used that 12v line for the 4e switched line and just leave that 12v switch (inside washer cabinet) on all the time and control it with the original 120v switch. It shouldn't matter where you get the 12v power from, switched or not, as long as the circuit has the required amps.

[DancinCampers]

If you are comfortable with changing the current wiring I would:

Use your oneplace 110v switch to control the electric side of the 12v relay by using it to send 12v (from current 12v lp switch). Cut wire going into switch from ems.

Remove current 110v wire from ems relay and run new 110v wire (hot/neutral/grnd) to heater assembly.

[Eddy W]

Where would I connect the switched 12 volt wire too in order to make the system work with my old interior switches ? The wires on the new water heater have different colour's than the new one. Eddy

[grtharris]

After looking at the Atwood Information Notice.
I would remove the existing 110VAC hot water switch and jumper around it. This will be the 110VAC supply to the water heater and maintain the load shedding from the EMS.
Then I would use your existing 12dc switch/lamp for gas trigger and pilot out. You will need to add one 12vdc switch for the electric mode selector put it some place convenient for wiring and use.
The 12vdc wires at the water heater plug are:
JW - Gas Trigger
JX - Ground
JU - Pilot out Lamp
Just noticed, 110VAC wiring in back 12vdc wiring in front of water heater.
This might also help.

[cbeierl]

This pdf file may help you figure out what you need to do: Water Heater Wiring Diagram Instructions for Converting GC10A-3E to GC10A-4E

[Eddy W]

Thanks Chris I have that wiring chart too but I was hoping to use the switches I already have in the unit and not have to install the switch they supply with it. I do not want to have redundant switches in my Panel and do not want to have to drill holes and mount the new switch. I would have thought Winnebago or Atwood would have some kind of kit to make it plug and play. I contacted both Winnebago and Atwood and they both told me its the other guys problem. Unfortunately its my problem. If I could spot where to hook up the wires to supply constant 12 vt power to the unit I can put a switch in there just to supply the 12 vt. The colours are all different on the wiring and nothing seems to match. Eddy

[DancinCampers]

Having taken a second look at the diagram that grtharris posted, I think a fused wire from your house battery solenoid with a switch, connected to WHT 2 would work. While traveling leave it on all the time (the relay would be energized) , and control the electric thru your existing switch. The battery bay is right next to your heater.

[cbeierl]

Note that all of the Winnebago-installed wiring should be labelled every few inches, so you should be able to sort out the existing wiring by using the Wiring Identification Guide and the wiring diagrams for your particular model coach from here: Winnebago Wiring Diagrams.