Using Aqua Hot system

[Tidwells@aol.com]

I'm REALLY wanting to figure out how to make the hot water work for hot showers on our recently purchased 1996 Prevost Royale by Monaco. I replaced the leaking radiator cap on the Aqua Hot unit and topped off with 50/50 antifreeze. I turned on the "Hot Water" switch under the kitchen sink, which has an indicator lamp which lit up. I've tried also switching on the "Instant Hot" switch under the kitchen sink.

The Aqua Hot's radiator cap is nice and hot, but no motor runs. When I turn on the not water knob on a faucet, I only get 2 or 3 seconds of semi-hot water, then it goes cold again. There is an Aqua Hot button on the right side of the driver's dashboard, but it doesn't seem to do anything. I would be grateful for any advice. Doug