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  1. #1

    Thermostat to relay wiring

    Thank you in advance for any help and indulgence with my amateur problem.

    I have a residential heat-only radiant system. The system has a number of zones, each controlled by a valve. The valves are connected to a relay board. On the relay board, I just need a thermostat to close the link on two input wires to turn on a zone.

    Most of the house is controlled by Upinor radiant thermostats which are simple 2-wire units, and I just hook up the two wires and it works fine.

    One zone was not wired, and I am installing a honeywell wireless thermostat to control that room. I am having some difficulty wiring the receiver to the relay board.

    I wired 24VAC out from the relay panel, Common to C and the hot to R (and bridged to Rc and Rh). The power seems to work fine, the receiver connects to the thermostat transmitter, and if I turn up the setting the heat circuit flips on the receiver and the heat light goes on.

    So I need to hook two wires from the receiver to the relay panel to close the loop when the system should be heating.

    I thought from reading the manual that the outputs should be the W wire, and a splice off the common coming into the receiver unit. But this does not trip the relay when the heat goes on.

    Can anyone help me with how I should wire to the red and white inputs on the relay panel?

    Thank you for your help.

    Honeywell Thermostat receiver

    Relay panel: red and white wires in from the top from thermostat

  2. #2
    Join Date
    Aug 2011
    Eastern Shore, MD
    sorry, please read the site rules, no DIY

  3. #3
    Join Date
    Jul 2004
    See? Do it yourself and you've already screwed up. The radiant heat is a whole different animal from a conventional heating/cooling system. The Upinor thermostat yes, has 2-wires but what's inside the box? Things the Honeywell system doesn't have. The dedicated radiant floor heating thermostat is a special thermostat with special control features. So you've wasted your money on the Honeywell system from my perspective.
    If YOU want change, YOU have to first change.

    If you are waiting for the 'other guy' to change first, just remember, you're the 'other guy's' other guy. To continue to expect real change when you keep acting the same way as always, is folly. Won't happen. Real change will only happen when a majority of the people change the way they vote!

  4. #4
    Join Date
    Jan 2006
    Near Atlanta, GA.
    Post deleted

    Links to other HVAC forums, and especially DIY forums, are totally against the rules.

  5. #5
    No problem. Sorry to be a rule breaker.

    For those who find this question on google and are looking for a solution, let me reprise what was deleted:

    Another forum, not to be linked to, had a member who in one sentence solved the problem for me and got everything working.

    Understand why the HVAC guys don't want DIY and apologize for treading on it. Not sure why they are so agro about it.


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