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Radiant Controls

I'm getting ready to install a 2-zone staple up system with 6 loops per zone.  With engineered floors throughout, except tile in bathrooms, I'm planning on supplying both zones with the same temp.  The Burnham Alpine has been recommended.  My question concerns the required controls...Since I am supplying the same temperature, is a manual mixing valve sufficient, or is an outside controller in conjunction with an electric mixing block required?  Looking to keep this system simple, but dont want to defeat the purpose of a modulating boiler...Any input would be appreciated.


  • CMadatMe
    CMadatMe Member Posts: 3,086
    What else is the

    Boiler doing. Domestic Hot Water? Any baseboard  zones? How is the radiant attached to the subfloor? Also, Burnham just recently announced a new control strategy for this boiler. Does the boiler that you plan on installing have the new control package or the old?
    "The bitter taste of a poor installation remains much longer than the sweet taste of the lowest price."
  • Jimmy_C
    Jimmy_C Member Posts: 2
    Boiler...Addl info

    The boiler is also supplying an indirect HW heater (Burnham Alliance).  No baseboards- radiant heat throughout.  The tubing is 1/2" uponor on 8" centers, secured to subfloor with aluminum emission plates.  Each loop is between 240 and 280' in length.  The fully modulating boiler operating controls include outdoor reset, domestic HW priority, and built in provisions for external staging controls.  Is use of the outdoor reset required to get the most out of this boiler?  If so, might I be better off choosing a modcon boiler without outdoor reset?
  • Simply Rad
    Simply Rad Member Posts: 172

    Use a mod/con boiler with outdoor reset.  I hope the Burnham has it.  Reset is the brain to the whole radian floor system.  Think about have only one heat temperature in your car, what would you do in spring and fall......roll down your windows!  This is what you are doing with a manual mixing valve, the valve is set to keep you warm in January.  The rest of the year its a  roller coaster ride, blasting the zone with too high of supply temps, then sit and cool of(air temp and floor temp) then blast again. Think about outdoor reset as the brain's behind cruise control.  Modulate the flame, modulate the supply temps and then you can even modulate your flows(now thats another subject).  Use outdoor reset to gain efficiency with lower supply temps. Use outdoor reset to gain comfort also with your a consistent floor temperature instead of blasting it with too high of supply temperature most of the heating season.  You will not regret it when using the reset.  The best part is that most boilers have DHW priority built in.  This means that the boiler can operate at low temps most of the time, until the  DHW calls and then the boiler will automatically run at higher temps to recover the hot water fastest.  
    Jeffrey Campbell
  • CMadatMe
    CMadatMe Member Posts: 3,086

    You should be fine with using the reset  provided you punch in the correct water temp numbers you need at zero. Burnham recently announed a chage in the control for the boiler. The control is called the Sage2 and was being put on all the boilers as of Nov 2nd. Make sure yours is the new version. They are no longer using the MCBA control. The new control will be able to run a second water temp.
    "The bitter taste of a poor installation remains much longer than the sweet taste of the lowest price."
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