Replaced my Dometic/Atwood GCH10A-4E hot water tank

[ftodaro]

I just finished replacing my Atwood GCH10A-3E with the newer version 4E.

This is the 10 gallon tank with heat exchanger and electric element option. Since my original install (3E) the replacement tanks (4E) are wired differently. The old version had 3 wires running to the control panel to operate the gas side and they had a separate AC switch located at a different location to power the electric element.

The new system eliminates the separate electric switch and runs a 4th wire to a relay at the back of the tank to power the electric element.

At first i was going to install their new switch but running a new 4th wire from my control panel to the tank is no easy job. The route would require I jump over the rear wheel well and all of that area is enclosed on my rig.

So I decided to leave the oringal switch in place to power the gas side of the heater like before and install a second switch and run a new wire to run the relay on the electric side of the tank.

Because the electric switch was not in the same location as the gas side switch, it was easier to run this 4th wire to the tank, in my case.

The point of all this is that if your going to replace your old Atwood hot water tank, they don't make the exact wiring configuration any more and it will take some planning to get the job done. The instructions are pretty good at explaining the difference between the old an new. It took me awhile but i figured it out. Running that new wire is the big issue as much of the area is inaccessible.