Aqua-Hot demand burner control?

[oneknight]

Has anyone succeeded in doing this?
I have an aquahot 400D in my no vegatouch Entegra Aspire.

I've toyed with putting in a second thermostat to trigger the burner at a lower temp than the electric (as used by older aquahot units) but can't find a spot to screw it in or a thermostat that will fit any existing taps into the tank.

I've read here about an idea of using heat demand from any zone to trigger the burner, but never seen anything concrete.

My thought is to leave both switches on, but only let the burner run when actually needed to keep up with demand.