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Need help choosing controls - an outdoor reset and more

Cliffy
Cliffy Member Posts: 24
Need help choosing an outdoor reset, it's really hard comparing units and knowing the ins and outs of each.  Would like it to monitor both the indoor and outdoor temperatures, along with warm weather shutdown. 



We have an 85% Burnham gas hot water boiler with two zones, each with a circulator, and it's controlled by a Taco SR504EXP box.  The Burnham ODR module lacks the indoor sensor and the warm weather shutdown, so we're looking at aftermarket.



The boiler has a tendancy to short cycle and is oversized for needs.  I've read contradicory information as to if a fuel economizer, like the Intellicon HW+, would be beneficial to address that.  Also reading about variable speed pumps and other things like bypass which might address short cycling.  What's the preferred choice for eliminating short cycling because of an oversize boiler?  We don't want the electronics to wear out prematurely.



Thanks for your help!





 

Comments

  • CMadatMe
    CMadatMe Member Posts: 3,086
    Taco PC700

    Just plug a Taco PC700 into the SR relay and be done with it. No indoor or outdoor reset control is going to help you with an oversized boiler. Need to install a buffer tank to give the boiler run time so you have a place to "park" the btus.. Sounds like you already have the IQ card, so use it and install the buffer tank.
    "The bitter taste of a poor installation remains much longer than the sweet taste of the lowest price."
  • gennady
    gennady Member Posts: 839
    edited June 2012
    taco I-series

    install taco I series 3 way valve, with outdoor reset and WWS . It will also resolve short cycling issues as well. Your boiler will become buffer tank.( if it is high mass boiler)
  • icesailor
    icesailor Member Posts: 7,265
    "I" Series:

    The 3-Way is nice but the four way is nicer.

    You're right, use the boiler as the buffer tank. The boiler will hardly run. At least that's my experience.
  • gennady
    gennady Member Posts: 839
    edited June 2012
    4 way

    4 way is good, but he will need additional pump installed.
  • icesailor
    icesailor Member Posts: 7,265
    Pumps:

    With the 4-way, and the additional pump, it will become an absolute P?S piping system unless you go on a flier and not follow the instructions on how to install the valve.
  • CMadatMe
    CMadatMe Member Posts: 3,086
    Water Content

    An ES25 only holds 5 gallons of water. Buffer tank is the better play. How did we go from boiler reset to system reset?
    "The bitter taste of a poor installation remains much longer than the sweet taste of the lowest price."
  • gennady
    gennady Member Posts: 839
    low mass

    yes, on low or medium mass boiler buffer tank is needed. for WWS DIGI SPAN
  • 04090
    04090 Member Posts: 142
    edited June 2012
    Curious

    What's the four way valve do that a three way doesn't?
  • CMadatMe
    CMadatMe Member Posts: 3,086
    Boiler Protection

    The primary reason is boiler protection. Here is a nice read on Mixing in hydronics.



    http://www.caleffi.us/en_US/caleffi/Details/Magazines/pdf/idronics_7_us.pdf
    "The bitter taste of a poor installation remains much longer than the sweet taste of the lowest price."
This discussion has been closed.