I have a tankless hot water heater and was wondering how to most folks are heating their water with their boiler? I could install a hot water tank and heat it in the winter with a sidearm exchanger and just turn of fthe thankless. I also thought of installing a plate heat exchanger prior to the tankless, but I don't know exactly how the tankless works. I think it works on flow not temp? Any suggestions would help, as I am planning my system. Thanks!