Click here to Find a Contractor in your area.
Welcome! Here are the website rules, as well as some tips for using this forum.

If you've found help here, check back in to let us know how everything worked out.
It's a great way to thank those who helped you.
Need to contact us? Visit

Coal Boiler & Outdoor Reset

KungurKungur Posts: 49Member
I am presently heating my house with a coal stoker boiler,Keystoker KA-2. My house is set-up for radiant floor heat. I am using a Tekmar 3 Way Mixing Valve #712 to maintain 130F water temp to my manifolds. The system works great but when we get the extremes like we have this winter and then the Spring and  Fall dyas with cold nights and warm days, I would like to consider an outdoor reset system.

Tekmar has an actuating motor for this valve and they told me that Model # 360 Control would be what I need.<a href=""></a>

As a carpenter/woodworker that put this system together with some help from others I was wondering about this set-up.

All I want to do is have the outdoor temp "adjust" the 3 way mixing valve as needed based on the outdoortemp. But the info on the Boiler Control 360 shows the pumps etc. being controlled. Can I just wire this to the actuating motor on the mixing valve only?

Would really appreciate your help.


  • Big Ed_4Big Ed_4 Posts: 1,188Member
    Sure you could

    But why not the whole boiler and save on the fuel and add comfort to your other zones .. Taco makes The I Series R mix valve with a built in outdoor reset for a radiant zone too.
    I have enough experience to know , that I dont know it all
  • KungurKungur Posts: 49Member
    Coal Boiler & Outdoor Reset

    Since I have the Tekmar already installed I really donot want to replace it. As for controoling the "whole" boiler. Not sure that is really possible with the coal boiler. So I was thinking to make it as simple as possible.

    So my question is still the same from the first post.

  • Big Ed_4Big Ed_4 Posts: 1,188Member
    edited February 2011

    I have a old brochure laying around here for 1909 for a manual counter weighted outdoor reset which operated the air damper of a coil boiler with a chain ...

    Seem like a waste using just part of that control but yes you can just use it for a motorized mixing valve ... I find there literature somewhat confusing and they may not show all the options ...
    I have enough experience to know , that I dont know it all
  • KungurKungur Posts: 49Member
    Any Other Comments?

    So anyone else have any advice?
  • RobbieDoRobbieDo Posts: 131Member

    I guess my question is, what are you trying to achieve? I'm sure the temp on the boiler is hot enough to heat the water to the 130 temp. If you can maintain 130 temp then you should be fine, I guess I'm confused?
  • Big Ed_4Big Ed_4 Posts: 1,188Member

    Just a recommendation , I understand you what to save a few buck , you are unsure and what to make it simple so no mistakes are made ... Control wiring I feel is another trade where I find most electricians are afraid of . Yes unwanted things can happen if not correct ..The control you bought is a very nice control and can control your hold system .. It is not a run of the mill control we run across everyday ..... Since you already own the control , call in the right guy and do it right ... Well worth the call . Just trying to help .... It would like me trying to build a seven gable roof ....
    I have enough experience to know , that I dont know it all
  • Randy BaergRandy Baerg Posts: 26Member
    outdoor reset mxing with a tekmar 360

    The tekmar 360 control can operate a 741 motor mounted onto your 712 three way mixing valve. It would be best to connect at least the pump for the manifold ('Mix System pump') to the control. That way it can turn on the pump when the thermostat calls and also provide Warm Weather Shut Down WWSD to disable the pump and save energy.

    The 360 can either control the boiler directly or enable it or do nothing with it. The choice depends on your system and your preference. If you don't want to control the boiler, or the system doesn't allow for it, then make sure you set the 360 Boiler Sensor DIP switch Setting = Return. The control then uses only the floating action mixing to keep the Mix Supply temperature at the calculated target. 
This discussion has been closed.


It looks like you're new here. If you want to get involved, click one of these buttons!