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Taco box only one zone has heating

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Hi 
My upstairs uses radiant heating. Taco box only has red light for Zone 1. Both Zone 2 and 3 pumps are cold. I’m not sure which zone my upstairs represents. I tested the thermostat - fan is working, AC is working but cannot bring up the heat. recall having heat upstairs two weeks ago. Sometimes I turn off the whole boiler and pump switch in the basement overnight cuz it’s too loud for me to sleep next door, then back on during the day. 

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  • ChristieTO
    ChristieTO Member Posts: 6
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  • neilc
    neilc Member Posts: 2,712
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    can you post a wider shot showing everything,
    boiler, circs, expansion tank, and all piping, one shot, or 2 from second angle
    known to beat dead horses
  • Big Ed_4
    Big Ed_4 Member Posts: 2,819
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    Radiant heat take a while to heat up to feel it's warmth....Try leaving the boiler on and not use any set backs in the thermostat . Leave it on hold..

    The radiant zone should have a mixing valve piped in ...

    There was an error rendering this rich post.

  • ChristieTO
    ChristieTO Member Posts: 6
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  • HomerJSmith
    HomerJSmith Member Posts: 2,483
    edited November 2022
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    recall having heat upstairs two weeks ago.
    What has changed? Wider photo, please.
  • ChristieTO
    ChristieTO Member Posts: 6
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    Nothing really changed except I turned off the switches occasionally cuz I was isolating in the downstairs bedroom next to the boiler room (too noisy). Weather has been very mild over the last two weeks so didn’t really use any heating at all. 
  • Karl Reynolds
    Karl Reynolds Member Posts: 63
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    What is the date code on the ZVC controller? Take the cover off and there is a white sticker in the upper left corner. It will look something like "10-16". Taco had a recall on many of these made in 2016 due to a faulty component issue.
    ChristieTO
  • HomerJSmith
    HomerJSmith Member Posts: 2,483
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    recall on many of these made in 2016 due to a faulty component issue
    I didn't know that. Thanks for the info.

    Cold pumps indicate that there isn't any power getting to the pump. HOLD ON! That Taco control box appears to be a Taco SR control box (SR506). The problem could be the Taco SR, the thermostat, or the wires from the thermostat to the SR506. You could jump the R & W thermostat connection for the cold pump in the SR506 and see if the pump starts. If the cold pump starts, then it is the thermostat or wiring from the thermo to the SR.
    ChristieTObucksnort
  • Karl Reynolds
    Karl Reynolds Member Posts: 63
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    There is a SR506 as well as a ZVC403 installed. I seem to remember an issue with the SR's also but more recently, going back a year or so.
  • ChristieTO
    ChristieTO Member Posts: 6
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    What is the date code on the ZVC controller? Take the cover off and there is a white sticker in the upper left corner. It will look something like "10-16". Taco had a recall on many of these made in 2016 due to a faulty component issue.
    Thanks. The previous owners installed the system in 2013. I kept the whole system on for 24 hours, and turned up upstairs thermostat asking for heat. Still nothing. 
  • hot_rod
    hot_rod Member Posts: 22,396
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    A stainless pool heat exchanger with nothing connected to it?
    Bob "hot rod" Rohr
    trainer for Caleffi NA
    Living the hydronic dream
  • HomerJSmith
    HomerJSmith Member Posts: 2,483
    edited November 2022
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    Gasp, Homer, you missed the ZVC behind the X-tank. I did see the Zone valve so it should have been obvious. Further analysis is warranted.

    So, what do the Taco 570? series ZV operate and what do the pumps operate. I assume, and I've been wrong more time than I care to admit, that the thermostats operate the ZVC and the ZVC opens the 570s and turns on the pump(s)??? and the SR turns on the boiler???

    Taco box only has red light for Zone 1. Both Zone 2 and 3 pumps are cold.
    Which box are we talking about? ZVC or SR, I'm assuming SR.

    Oh,boy, I'm out to lunch on this one.

  • ChristieTO
    ChristieTO Member Posts: 6
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    I asked my husband to go up to the attic to turn the upstairs furnace switch off then on - Problem solved. Thanks everyone!