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Taco relay

LarryBelanger
LarryBelanger Member Posts: 1
in A-C, Heat Pumps & Refrigeration

taco 503 relay not operating all zones

Comments

  • EdTheHeaterMan
    EdTheHeaterMan Member Posts: 9,260
    edited September 8

    More info needed

    Let's start with diagnostic lights on the SR 503. Is the green light on?

    Edward Young Retired

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

    SteveSan
  • SteveSan
    SteveSan Member Posts: 256

    Metal or plastic cover? Like Ed asked, green LED on? Do you have voltage at NH coming in? Are the fuses good?

    What if you jump the t-stat wires on the control, does that bring the zone on?

    Please give Taco Technical Support a call Mon-Fri 8am-5PM EST 401-942-8000 and just ask for Tech Support.

  • HomerJSmith
    HomerJSmith Member Posts: 2,628
    edited September 9

    It's an SR503-4, I guess. Which zone is inoperative? What kind of thermostats? Does the corresponding led lite when the thermostat calls for heat?

    Check and make sure that all the screws to wiring are tight (turn off power when doing this). If it is the priority zone, move the priority switch off and on several times. If you don't need priority leave the switch in the off position. Take a closed end wrench and tap the relay lightly on the inoperative zones (does that help?).

    You can get a cheap digital volt meter at Harbor Freight or Home Depot and set it at 120V ac setting and check each N-H screw for each zone pump connection and see if the meter reading is 120 Volts. The thermostat for that zone must be set above room temperature and the corresponding led is lit.

    That would be a start.

    I guess it would be prudent to ask why you think , the "taco 503 relay not operating all zones".

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