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Taco SR503-4 relay

My question is, I installed the taco sr503-4 switching relay. The jumper that goes between ZC and ZR, do I have to install the jumper between those two terminals?


    HVACNUT Member Posts: 5,270
    edited November 2021
    So I walked into WindowRama, went up to a bay window, and asked the sales rep "Will this fit in my wall?"
    What model aquastat do you have? If it's "cold start", then yes, the jumper gets installed. If the boiler has a tankless coil, then ZR,ZC on the relay should get wired to ZR,ZC on the aquastat. 
    Did you have 3 separate switching relays and upgraded?
    Gas, oil, mod con? There are reasons you might want to delay the start of the circulators.
  • heavenlyheating
    heavenlyheating Member Posts: 3
    it’s a taco SR503 switching relay, it had two separate relays and I installed the taco relay. I will install the jumper and see if that helps. Thanks for the advice 
  • EdTheHeaterMan
    EdTheHeaterMan Member Posts: 6,174
    Sometimes, even Heavenly People just can't take a joke!
    Or understand about the window of Sarcasm.
    Or answer the simple question about what aquastat is on their boiler.
    I hope the jumper works!
    Good Luck and Happy Thanksgiving.

    If it does not, then bring back more information Mr. HH

    Yours Truly,
    Mr. Ed
    Edward F Young. Retired HVAC ContractorSpecialized in Residential Oil Burner and Hydronics