Aquastat temp on a steam boiler

gandyman

Hi everyone,

I'm the proud new owner of an old burnham holiday gas fired steam boiler. I've researched a lot and can't find this answer. It has an aquastat on it, which is currently set to 100F. I see lots of recommendations for hot water systems to be set at 140F or higher but I can't for the life of me find what temp I should have mine at. Is it normal to have an aquastat on a steam boiler? Most pictures I see of steam boilers don't have this at all. My boiler does not provide my hot water for showers, etc. There is however a hot water zone in the basement with a circulation pump on it, which I do not, nor do I plan to use. Any help here would be appreciated.

Thanks,

JohnNY

Does it have an abandoned hot water coil in it?

gandyman

Hi John,

That I do not know, this sucker is probably about 50 years old so it is quite possible. Any tell tale signs?

Steamhead

The aquastat should be part of the control system for the basement hot-water loop. If only that loop is calling for heat, it will keep the water from getting hot enough to make steam.

gandyman

I see. So it's alright to leave it at 100F? I won't be using that loop at all. Thanks for your time, guys!

Steamhead

Set it to about 160, as long as this does not make the boiler stay that hot all the time. If it does, turn it all the way down.

If the latter proves true, and you decide you want to re-activate the loop, it should be easy to change the wiring so the burner only fires when either the loop or the steam is calling, and if only the loop is calling, to keep steam from being generated.

gandyman

Thank you, Sir! So this will keep the boiler's water at 160 and that is desirable during the heating months?

Steamhead

No, you don't want to always keep it 160. That's wasteful. If it does that when set to 160, turn it down.

gandyman

Ok, thanks!