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TACO SR503 Red Zone Light Constantly Switching ON/OFF

notthesameninja Member, Email Confirmation Posts: 1
I have very little knowledge of the technical side... so as the title explains, I am noticing that my TACO SR503 Switching Relay constantly flickers the RED Light. My guess would be that it's due to a lack of electrical current maybe? it switches ON for 2 seconds, and powers the Circulatory Pump for a few seconds, then turns OFF... and the whole process repeats. Any help would be appreciated, Thank You!


  • SteveSan
    SteveSan Member Posts: 89
    Please call into Taco Tech Support @ 401-942-8000 Mon-Fri 8AM-5PM EST. If you can be in front of the control and if you have a multi meter that would help as well if we need you to take a voltage reading. It could be as simple as a loose wire connection or if you have some type of power robbing t-stat you might just need a resistor. Also, does your SR control have a metal or plastic cover? That will let us know what generation control you have.
  • STEVEusaPA
    STEVEusaPA Member Posts: 5,176
    @SteveSan this has to be the most popular tech support call with everyone going to wifi t'stats.
  • SteveSan
    SteveSan Member Posts: 89
    Especially where to connect the com wire, most miss the small green terminal on the left one side 24vac and other side com.