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Help me complete the job. Taco SR501-4 Switching Relay and disconnecting the old tstat

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avklotz
avklotz Member Posts: 2
edited November 2022 in THE MAIN WALL
I told my furnace guy I could hook up the new thermostat no problem, if he installed the switching relay. Well 2 weeks later I forgot what he told me to do. In this pic the old thermostat is still connected to the oil furnace with the 2 wire nuts: R wire, W wire and coiled G wire. That old tstat operates normally. What I would guess is that those R & W either go into the TT slots under R & W on the relay, or they go on one of the 4s, 5 or 6 below but looking at the schematic.





In the switching relay, three wires to the new thermostat were connected by the tech, R, W, G and there is one additional wire, B (blue, you can see he coiled it around the others). Im not sure whether that wire is supposed to be the common wire, going to power the new thermostat. Its a honeywell 6500, but he left B coiled and disconnected making me think its not needed here



Thanks for any support!

Comments

  • EdTheHeaterMan
    EdTheHeaterMan Member Posts: 8,157
    edited November 2022
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    On the thermostat end G is not used. G is there to operate a fan on a air conditioning system.



    At the thermostat, swap the green wire. with the C terminal and do not use the blue wire at all. At the Taco SR501 do not change the thermostat wires at the top.

    At the 5NO and 6 terminals, place the red and white wire that go into the boiler on the boiler housing in 5NO and 6. This will operate the boiler when ever the relay is activated. The other 2 wires that are on the blue wire nuts are no linger used. they probably go the the old thermostat you are no longer using.

    Edward Young Retired

    After you make that expensive repair and you still have the same problem, What will you check next?

  • STEVEusaPA
    STEVEusaPA Member Posts: 6,505
    edited November 2022
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    So call your furnace guy before you wreck it. What you're showing is very wrong.
    You spent considerable time going online, searching, landed here, created an account, created a post, attached pictures, and you could've cleared it up with a 2 minute phone call...smh

    There was an error rendering this rich post.

  • avklotz
    avklotz Member Posts: 2
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    @STEVEusaPA put in the call, registered, asked and got replies!
    @EdTheHeaterMan your post was correct. Would it matter if 5NO & 6COM are switched in this setup?
  • EdTheHeaterMan
    EdTheHeaterMan Member Posts: 8,157
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    avklotz said:


    @EdTheHeaterMan your post was correct. Would it matter if 5NO & 6COM are switched in this setup?

    When only 2 wires are involved. it does not matter. The problems start when you have 3 wires. You need to know which one is R and which one is C and which one is W (like on the thermostat side)

    Edward Young Retired

    After you make that expensive repair and you still have the same problem, What will you check next?