Steam boiler Hot Water coil

Guy_6

It sounds like the tempering valve, sometimes known as the mixing valve, is not functioning. Perhaps some debris became lodged in it during the changeout. The aquastat will only regulate the hot water temp. when there is no call for heat. When the boiler is making steam, it is up to the mixing valve to add cold (domestic) water to the hot (domestic) to obtain the correct temperature.

James Bates

Steam Hot Water coil too HOT

in 35 year old model 572 steam boiler. About a year ago the coil was removed in order to replace a leaking gasket. What would make the hot water reach steam temperatures? This occurs after the boiler has been chugging at full tilt for a while.

James Bates

Steam Hot Water coil too HOT

in 35 year old model 572 steam boiler. About a year ago the coil was removed in order to replace a leaking gasket. What would make the hot water reach steam temperatures? This occurs after the boiler has been chugging at full tilt for a while. What could have changed to make coil now way to hot?? Alfred/Jim

PS: aquastat was set too 150, but is now set to 140 with same result, steamy hot water.

bob young

instant tea & coffee

looks like you have no proper tempering valve just a primitive globe valve bypass set-up. not a very sophisticated piping arrangement. the globe valve is makeshift at best, useless at worst case scenario. remedy : repipe properly before someone gets scalded. you could probably make tea straight from your faucets.