I have a 26' Tollycraft with a 6cyl Volvo TAMD40 diesel engine. I installed a new Raritan water heater. The previous owner had removed a water heater and left the wiring and plumbing in place. The 120vAC reconnected fine and the system is working great while at the dock. The heater has a heat exchanger to allow heating of water while under way. The instructions tht came with the heater just say to hook it into the boats cooling system. My question is this: Where do I tap in? As far as I can tell, all of the cooling system is integrated with the engine and heat exchanger with no external hoses? There are two plugs in the engine heat exchanger, and was wondering if there is a possibility (of course there is always a POSSIBILITY) that that may be an option for this project. Has anyone had expereince with this particular set-up? Is there some source of documentatin that may guide me? I have an engine overhaul manual from Volvo, but that lends no clue. Any help would be appreciated