Aquastat Setting for Water Zone off Steam System

tbertz

I have two water heat zones pulled from a boiler used for a steam system. The boiler is about 5 years old.  The water zones were added about 2 yrs ago when we had construction on the house.  The zones seem to be struggling to heat the two rooms.  So I checked the aquastat temp and diff.  The auastat is a Honeywell L4006A and was set at 130 degrees and from what I can see the diff was set at 30.  I raised the temp to 180.  It corrected the issue with the zones, but the boiler was running more often and seemed to ignore the thermostat.  So I started backing down.  Now I am at 140.  I have not touched the diff.

Would love to hear any suggestions on the temp and diff setting.  Maybe something else I should consider?  BTW, I am a homeowner, not a professional.

Thank you, Bill

Steamhead

Does the aquastat

keep the boiler hot all the time, or only when the hot-water zones are calling for heat? 

tbertz

Aquastat Response

Thanks for your response.  The aquastat does trigger the boiler.  But when i had the setpoint set at 160 or above, the boiler was making steam regardless of where the steam system thermostat was set.  For example, the steam system thermostat was set at 64 degrees and the house temperature rose to 75+ degrees.  So I turned the setpoint back down and the boiler shut off.  If I set the setpoint at 140 or below, the water zones struggle to maintain the room temperatures currently set at 69 degrees.  I have not touched the diff which is set at 30.

Bill