Do you have a stand alone hot water tank that your boiler heats up or a coil in your boiler? If you have a tank why not just plumb it into your coal stoves' coil and turn the burner off!Kendrickson wrote:The Harman diagram shows the coil plumbed into the water heater at the drain on the bottom and the pressure relief at the top. Would I be able to use this same setup on my oil boiler (using the boiler's drain and pressure relief)? It is costing me 100 dollars a month just to run my boiler for my hot water needs. It would be nice to keep the boiler hot using a coil on my stove instead of using gold......er, oil.