Outdoor Reset

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Posts: 1088
Joined: Mon. Apr. 24, 2006 5:40 pm
Stove/Furnace Make: EFM 520
Stove/Furnace Model: GOODBYE OIL COMPANY
Location: Dallas, PA

Post Wed. Jun. 18, 2008 2:55 pm

I understand the concept of setting the boiler temperature lower in the warmer weather and hotter in the dead of winter. I've seen TACO, B & G, and Honeywell all have zone controllers with the outdoor reset feature. The boiler temperature (low and high limit) are on the aquastat. They are hard wired by way of the adjustment dial, at least on my Honeywell on my oil unit. So how does a zone controller adjust the boiler temp? Do you need to change aquastats so it can communicate with the zone controller or am I just being as dumb as a bag of rocks?

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Posts: 2966
Joined: Mon. Feb. 25, 2008 4:24 pm
Other Heating: OBSO Lennox Pulse "Air Scorcher" burning NG
Location: Lower Fox Valley = Wisconsin

Post Wed. Jun. 18, 2008 3:29 pm

browse this link!
**Broken Link(s) Removed**look at the literature for the model - lots of great information as to how and why and what

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Posts: 3030
Joined: Fri. Dec. 23, 2005 12:45 pm
Stoker Coal Boiler: Alternate Heating Systems S-130
Coal Size/Type: Anthracite Pea
Location: Sykesville, Maryland

Post Wed. Jun. 18, 2008 6:37 pm

Check the downloads on Taco's site for several methods to control the water temperature in one or more hydronic zones. See:

http://www.taco-hvac.com/en/products/Radiant%20Ma ... tegory=170#

Also check this hydronic heating design site:


Hydronic design software allows what if designs of several different designs. A limited capability version of this software in included with John Siegenthaler's book, "Mordern Hydronic Heating"



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