busted tankless coil

xxxxxx

oil boiler locked out on safety extremely dirty yrs. since last service, leaking water from faceplate only when boiler goes cold.replacing a 5gpm coil in an oil fired water boiler with an electric waterheater by its side. i noticed alot of shutoffs above water heater (2) on cold into w/h mounted parallel to each other then T s or splits and cold flow going to d/ coil, also between w/h & riser of boiler (2 )ball valves with fast fill in center, ends up eventually tying into heating pipes with expansion tank #30 nearby. tankless appeared to be shut down for a while. ball valve only prevent from boiler water going domestic, also combintaion of 1/2 and 3/4  copper.is this possibly reason for busted coil? whole layout seems a little hinky and not just for the backflow issues. boiler shuts down for summer by the way. with this information given what would be the most beneficial  piping layout, easy answer is replace tie together, and open ball valve to domestic however i think a better layout would be permanent solution any thoughts welcomed and appreciated

billtwocase

blank plate

the gasket is what is leaking when cold. If you no longer get hot water from the tankless, I would recommend that you have a professional replace it with a blank plate and new gasket. This would be best done in the spring/summer, should bolts break, and the heat is done for a while. Is the boiler worth the expense? What unit is it and age?

Ron Jr._3

I agree with Bill about replacing

with a blank plate if they don't need the coil . But , other than the coil gasket leaking , is the coil itself busted ? Is the coil leaking into the boiler internally ? If the valves to the coil were shut there's a good possibility pressure built up so high that something blew out inside . We always leave one of the pipes open to the system when we add a water heat to a system with a coil .