winter aquastat settings

Mark_60

Mark,
That aquastat is a safety device and should NOT be used the way you are using it. If you want to gain some efficiency put in a Tekmar control or a Beckett Heat Manager. You should leave the settings at 180-160 and walk away if that is giving you ample heat in the colder months. Also, you don't want to set the low limit under 140 to prevent condensation and premature failure of your boiler.

mark_65

winter aquastat setting

I live about 70 miles north of New York City. I have a Peerless boiler with domestic hot water, Beckett burner, and Honeywell triple aquastat. In past years I had set the winter hi and lo limits at 180/160, and summer at 140/120. When it got cooler this year and I needed heat I moved the limits to 160/140. 160/140 has been sufficient so far to heat the house adequately. As long as the lower settings are sufficient to heat the house, is it more fuel efficient to use them rather than the 180/160 that I had used in past winters. It seems that one downside to the lower settings is that burner and circulator must run more often to produce the same amount of heat (and so use more electricity), but are there other disadvantages? In general, for fuel efficiency, should the lowest settings that still provide comfort be used, or is running the boiler hotter in some ways better?

Rookie_4

You pretty much answered your own question. "The burner"
runs more often to give you the same amount of heat as you get when set to 180*/160*. The more the burner runs the more oil you are using. You are probably running a .85gph nozzle @ 140psi which will use 1.05 gals. for every running hour. 180*/160* is common and 200*/180* is also.
Good Luck..............ROOKIE

PatchoguePhil_2

I don't think so

If you need 'x' amount of BTU's to heat the home in a day, then 180*/160* will use more oil than 160*/140*. The burner will be running more with a setting of 180*/160* just to maintain the higher standby temps.

Icy L.I.

Is a 50 degree spread too much?

I've gone to 140/190 for monoflow system in Long Island home - is this bad? With higher low end settings, the circ often kicked out due to low temp right after starting up, presumably because of the mass of cold water being pushed through from the inaccesssible crawl space. Suspect circ is oversized, but that is another post.

Regarding safety - is expansion the issue? Provided that surge tank accomodates volume increase, all should be OK, no?