I currently have a 145000 btu boiler that is old and sometimes it shuts off when the water table gets too high, or the oil line gets clogged etc. my house has a weak electrical system, and a very underutilized propane tank- gets filled once every year or two. I was thinking about getting a propane tankless heater, and curious if there is much to adding this to my home system. The boiler does all the heat and the hot water for the house. I would have to run plumbing from the propane to the tankless. I would install this in a drafty basement (300 year old house with muddy dirt floor and 5-foot ceiling in the basement). I would use a mixer valve and tee in to the boiler’s supply line so it would just back up the hot water from the boiler. Other than the propane supply piping, mixing valve, cold in and hot out, what else would I need to install for a heater like this? Thanks!