[cfelton]

Man Spare, we must be on the same wavelength. I slept on it and thats what I thought about! I'll try running the bathtub half full of really hot water and putting a little air on it. I just put a new riser/tank on it, and thinking about it, looks like the whole exhaust manifold and riser would have to fill completely up before it could run over into the seawater pipe on the riser and back down into the heat exchanger (I think). Its gotta be the heat exchanger, I'll let ya know what I find out. Thanks Spare!!