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Help in choosing Taco reset control

Jon L.
Jon L. Member Posts: 13
The installed boiler is a Dunkirk QL100 non-modulating condensing boiler w/3 fin tube zones and an indirect water heater zone. I am using the expandable Taco switching relay, and want to incorporate the Taco PC700 outdoor reset control. If I go this route, will the priority DHW feature of the switching relay override the tentative lower temp. set of the reset control allowing high temperature for the DWH? There is no reference in Taco literature addressing this. It is somewhat addressed in literature for their PC702 reset. This model reset control however is for a two stage boiler, but makes reference to domestic hot water demand output. (it's also $100.00 more)
Thanks in advance for any input you can offer.


  • Glenn Sossin_2
    Glenn Sossin_2 Member Posts: 592
    Bypass reset curve on DHW demand

    Connect the PC700-2 cable to the add-On interface on the Taco Zone Control. Ensure the Mode switch on the Zone Control is set to Reset.

    You need to use any Taco Expandable Relay Unit (EXP model). Make sure indirect is hooked up to the priority zone. It will automatically bypass the reset curve on a DHW demand and boiler will fire to what ever the high limit is set at.
  • Jon L.
    Jon L. Member Posts: 13
    Thank You Glenn...

    Thank you Glenn, That was the explanation I was hoping to hear. You guys are great.
  • ScottMP
    ScottMP Member Posts: 5,884

    Look into the PC605 plug-in power-port card. It will only run the Priority for one hour and then shut off the priority. Nice protection in case of a bad circulator or air bound coil.


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  • Jon L.
    Jon L. Member Posts: 13

    Thank you for reinforcing what I thought was a good purchase.
    I actually ordered the PC605 (on backorder) and the PC600 for priority post purge. They both sounded like worthwhile investments. The job should all come together fairly soon.
  • John Barba
    John Barba Member Posts: 166
    taco job

    Hey Jon L --

    Could you e-mail me some pictures when you're done. I'd love to use them in training. Thanks!
  • Jon L.
    Jon L. Member Posts: 13
    I'm not a pro John, but...

    I'd be happy to forward some pictures when done. Having seen your signature I'm sure your interest lies with my use of the Taco products. I'm a home Inspector by trade, and am helping my son with this install. You will be happy to know that your products seem to be the preferred choice locally. (Plattsburgh,NY) As well, they seem to be perfect for our job.
    Armed with some pretty good basic knowledge, Dan's books, and advise from the experts at this site, the job has moved along quite smoothly.
  • Joe Mattiello
    Joe Mattiello Member Posts: 703

    yes, DHW always over rides the reset control. The PC700-2, and the pc702 two boiler staging control both offer outdoor reset.
    Joe Mattiello
    N. E. Regional Manger, Commercial Products
    Taco Comfort Solutions
This discussion has been closed.