Hello all welcome back to camping season. Im a relatively new gtc owner and first time rv owner and I have questions on how the hot water heater works. I have no owners manual

First what I know:
I know hot water is produced one of two ways, one by using the heat of the engine while its running, and two by using the110 power water heater under the sink. That's about all I know.

I'm wondering does the knob with the red light next to the stove turn on the water heater. If so should I hear something, I see the light illuminate red but that's about it, and that seems to happen whether I have110 power or not so I'm not sure on that part

I just replaced the water pump and had the copper lines repaired, the system is now holding water. Does turning the pump on automatically fill the 7gallon water heater?

Then as for running the water through the engine, obviously you have to start the rig, but then does the clean water automatically start running through the engine, or is there something I need to do to make that happen.

I love my gtc and am determined to get it fully functional, and any help would be appreciated.
Thanks
Chris

The switch on the bulkhead by the stove energizes the 110 VAC heating element in the water heater. No sound required. The other heat source, the engine cooling water, heats the water in the heater via an internal heat exchanger when the engine is running and the isolation valve is open. There should be one in a hose near the cab heater at the left (as you look into the open hood from the front). These systems work very well, the downside being that if you aren't running the engine, you won't have hot water unless connected to shore power or powering the AC panel with the generator. These were very high end units at the time, and not used in most RV's.

I should have asked you which rig is yours?

I should also have asked you to post a photo of the "knob" near the stove. Most GTC's have a standard toggle switch with a red pilot light.

I guess I overlooked that switch next to the stove. I see What your talking about, if you flip the switch the red light turns on only when 110 power is on, so that must be it. I've yet to try the hot water but I'm camping this weekend so will see if it works.
So I'm assuming I just turn the water pump on, preassurize the lines, hit the switch for the generator and then for the hot water heater, I'm assuming wait a few minutes for it to warm, and it should work... Am I missing any steps. Do I need to do anything to make sure the water is attempting to hear the other way (engine heat)?

As for the knob I was taking about, I'm starting to think it's been added on after manufacturing. (One of the many switches added that I have no idea what they go to... Yet..,. I Attatched a picture of the knob.

And as for which rig I have, I own (the John Deer edition ) 73.... Original owner was a John deer enthusiast and painted the exterior to match. I bought it here in my home state of California last October, (my wife and I first purchase as newlyweds, we love all things 70s)

Great looking GTC! Sorry to have missed your reply, but here I am anyway. Mine is the white/red/orange one with the unfortunate gelcoat. It's number 2 on the list of photos. All the mechanicals are new/rebuilt/remanufactured since I bought it in 2010. New water tank, pump and pressure tank - too much to list. It takes considerable time for the tank to get hot all the way, so don't expect "a few minutes". You'll learn quickly tor conserve your hot (and cold) water! Interesting knob and wall plate.

Looking at that knob and cover plate again, it looks like a thermal breaker of some kind. Maybe you could trace the circuits or look around all the nooks and crannies to see if you can ID what it controls. BTW, I hope your first trip was a good one.

i have a light switch thingy behind my drivers seat on the cabinet for this i think...ive never used it so i dunno but i cant find anything else efected by that switch

Does the red pilot light glow? It makes sense to have the switch in that location, since that's where the heater is.