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Multiple Circulator & Zone Valve Relays with Post-Purge?

Steamhead Member Posts: 14,863
Looked at a HW job yesterday with six circs and four zone valves. The control system for this looks like someone threw a whole bunch of spaghetti onto the wall and it stuck. Since we'll probably be re-wiring this, does anyone know of a mutiple circulator or zone valve relay that will allow the circs to purge some of the heat out into the zones after shutting off the burner?

All Steamed Up, Inc.
Steam, Vapor & Hot-Water Heating Specialists
Oil & Gas Burner Service


  • hot_rod
    hot_rod Member Posts: 15,065
    does it have an indirect?

    if not the priority relay output on most pump relays has a post purge. I know the Caleffi ZSR has a non-adjustable 2 minute post purge on relay 1
    Bob "hot rod" Rohr
    trainer for Caleffi NA
    Living the hydronic dream
  • STEVEusaPA
    STEVEusaPA Member Posts: 5,326
    Make your own

    Unless someone has some commercial controls experience, you may be better off getting your own relays/contactors (Grainger's) and making it yourself.  I know a real wizard up here in the Philly Suburbs who used to build/service elevators before he started his HVAC career. I've seen him do some interesting things with relays and contactors.  Send me a message if you want his info.

    Tekmar boiler controls (I know the 374 does) also post purge on the DHW contacts ( think until 10 or 20 degree drop).
  • Mad Dog_2
    Mad Dog_2 Member Posts: 3,471
    Wow that's cool stuff , steve. Mad Dog
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  • wogpa67
    wogpa67 Member Posts: 238
    Th e Honeywell AQ2000 series does, also the Exp Taco has available plug in cards to do that.
  • Robert O'Brien
    Robert O'Brien Member Posts: 3,390
    AQ2000 is the way to go,does that and a whole lot more. Why reinvent the wheel!
    To learn more about this professional, click here to visit their ad in Find A Contractor.
    Ron Jr._3Zman
  • Ron Jr._3
    Ron Jr._3 Member Posts: 603
    Does,the AQ have the capability of being used for circs or zone valves with the same control ?
    Robert O'Brien
  • MikeJ
    MikeJ Member Posts: 103
    installing in floor heat for all floors for a new house, used gypsum over pex for the main level and 2nd floor. I will have 5 pumps for the floors, one pump for air handler, one for indirect tank.
    counting on not using air handler much,
    any ideas for switching relays?
    they have a huge shower 5-6 heads, not sure if I want to stop making hot water and switch to floor, 80 gallon tank.
    Robert O'Brien
  • Joe Mattiello
    Joe Mattiello Member Posts: 622
    Taco offers several controls to facilitate wiring similar to yours, including the SR506-4 EXP with 120 volt output for up to 6 circulators. It has a post purge feature built into the control, which is unique to the priority zone 6, normally used for DHW. If you prefer, you can use zone 6 for another heat zone, and use the post purge feature for that zone. However, it will not work on all the zones, as you mentioned. Frankly, I don't think anyone makes a control that enables you to purge residual heat, and dump into all the zones. Usually, the purge is synonymous with DHW.

    For your reference, I attached the Taco zone control wiring guide which is a great resource when challenged with a wiring issue. Please advise if you have any questions or concerns.
    Joe Mattiello
    N. E. Regional Manger, Commercial Products
    Taco Comfort Solutions