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Taco pc700 outdoor reset.

The boiler starting temperature is typically the temperature at which you would need to actvate the boiler to get it started for heating the building. The default setting for this is usually the same as the room temperature you are trying to target or 70°F. The Minimum Return Temperature for an SCG Cast Iron boiler is 135°F to 140°F because that is the temperature at where the flue gasses within the boiler can start to condense. The typical settings for a Baseboard Application are as follows:

Boiler Start - 70°F

Outdoor Start - 70°F

Boiler Design Temperature - 180°F to 190°F

Outdoor Design Temperature - Coldest Sustained Outdoor Temperature for your locale (usually 0°F to 15°F)

Boiler Minimum temperature - 135°F to 140°F

Differential - Set to Ad (Auto Differential)

WWSD - Warm Weather Shutdown is set to Outdoor Temperature point where heat is no longer needed (usually 70°F to 75°F)

Some modifications to Boiler Start Temperature and Outdoor Design Temperature may be neccessary depending on whether you have air handlers and your geographic location. Hope this helps.

Glenn Stanton

Manager of Technical Development

Burnham Hydronics

U.S. Boiler Co., Inc.


  • Dan C._4
    Dan C._4 Member Posts: 70
    taco pc700 outdoor reset control

    what does the boiler starting temperature mean and what should it be set at? I read it in the instructions and it doesn't make sense to me. Also The outdoor temp is 27 and the boiler target temp is 166 but the boiler fires when it is at 172. How do I fix this. Also does anyone know the minimum return temp for the burnham SCG boiler?
  • Dan C._4
    Dan C._4 Member Posts: 70
    Thank you glen

    That was VERY helpful. Tank you very much. The radiation is Cast iron baseboard. Also Is the minimum boiler temp the supply temp or the return temp? Should I add 20 degrees to that or is it already figured in?
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