aquastat on steam return set to maintain boiler temp ?

sherpa

i could not see any evidence of domestic hot water ever being connected. this system looks original.

sherpa

why maintain boiler temp based on steam return?

short cycling steam boiler (old snow man).
found an la409 aquastat from minniapolis honeywell(petro mizer) maintaining boiler temp based on a steam return line below the water line. why? is this for comfort? it can't be fuel efficent.

Unknown

It might be

or might've been connected to a heat timer . Or that was the only place to get an aquastat in the water ?

Brad White_202

I agree or

it could also be a high limit for a HW zone or domestic HW production.

If for a Heat Timer as Ron suggested, that is to sense the completion of a cycle, a full warming of the system. If the 'stat is on the return side of the Hartford Loop (if there is one, I hope so...) then I suspect the Heat Timer.

If on the boiler side, I would think it is a high limit to keep the boiler from steaming when making DHW.