Quote Originally Posted by Gary View Post
Should we elect to go the direct heating route, ideally the supply of fully heated water would be sufficient to keep the tank level from dropping too low during periods of peak water usage.

But if it is not sufficient to maintain a minimum tank level, we need a means of bypassing the water regulating valve to provide full flow through the condenser. Perhaps a dual float switch and bypass solenoid.

As the tank level drops, the first float switch turns on the AWHP in feedwater heating mode. Should the level drop further, the bypass is energized by the second float switch, bringing the level back up (with partially heated water) and then de-energizing the bypass.
Wouldn't the cold water then mix with the hot water & we'd end up with similar results to the pump-round route? By pump-around route, I mean tank->pump->hp->tank, not the external hot water loop (Grunfos-style).