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One zone too hot

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zvalve
zvalve Member Posts: 83
edited March 2022 in THE MAIN WALL
How does one deal with one zone that is way too hot. It was set at 67 but reading 80 on thermostat. It’s a two zone hydronic system. The batteries in thermostat regulating zone in question may have been dead.

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  • EBEBRATT-Ed
    EBEBRATT-Ed Member Posts: 15,764
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    @zvalve

    Depends on weather it is zoned with circulators or zone valves.

    Assuming you replaced the stat batteries

    If it is zoned with circs you could have a bad or stuck flow check valve. It could be located inside the pump or remote in the piping. That is the most common cause. In this case you would have two pumps

    If you have one pump and zone valves you could have a bad or stuck zone valve or, loose wire or bad thermostat

    post some pictures so we can see what you have
  • zvalve
    zvalve Member Posts: 83
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    thanks photos
  • zvalve
    zvalve Member Posts: 83
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  • Aluvaboy
    Aluvaboy Member Posts: 29
    edited March 2022
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    zvalve said:

    How does one deal with one zone that is way too hot. It was set at 67 but reading 80 on thermostat. It’s a two zone hydronic system. The batteries in thermostat regulating zone in question may have been dead.

    Recently I ran into an issue. I replaced the power heads for the Zone valves in a two zone system. They were Erie power heads. You can just pop a new power head in with ease. But when I reconnected the valves, I accidentally mixed up the Zone 1 and Zone 2 heads wiring vs the thermostats. So when Zone 1 thermostat is calling for heat, the Zone 2 zone valve opens and circulates water in Zone 2. But because Zone 1 thermostat is never satisfied, it keeps on heating up Zone 2 until the Zone 2 rooms are way too hot. And still the boiler will not stop. I first thought it was air entrapment in the zones and purged a few times. Still the problem persisted until I found that the wiring was mixed up.

    Did you do any modification with the wiring recently?
  • zvalve
    zvalve Member Posts: 83
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    Years ago I replaced a zone valve and thought I got the wiring right but I’ll double check, thanks
  • EBEBRATT-Ed
    EBEBRATT-Ed Member Posts: 15,764
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    @zvalve you most likely have a zone valve/thermostat/wiring issue on the overheating zone.

    Check for 24 volts at the offending valve. They are usually power open and spring closed. There should be a lever on the valve head to open and close the valve
  • zvalve
    zvalve Member Posts: 83
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    I tried closing lever and boiler went off is that normal? Thermostat was wired at wall plate with white and green wire from wall on W terminal together so Itried separating wires white wire to W on wall plate and green wire  to G, no change. is this right? System  is hydronic heat only with gas fired boiler
  • zvalve
    zvalve Member Posts: 83
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    Manual switch on valve body in question  is not functional and level is disconnected from spring and flopping around
  • Aluvaboy
    Aluvaboy Member Posts: 29
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    zvalve said:

    Manual switch on valve body in question  is not functional and level is disconnected from spring and flopping around

    I guess it is time to replace the zone valves. The end switch in the zone valve is there for a reason!
  • neilc
    neilc Member Posts: 2,712
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    2 wires under 1 terminal at the stat base would be the problem keeping your heat on,
    at the stat base, try disconnecting one wire and see that the valve closes, it should,
    does it ?

    then,
    you still have an issue at the stat with the wires landed,
    one should be on R or RH, the other on W, or maybe C and W?
    those are your heating terminals,
    G is usually a fan manual/auto option for furnasties and heat pumps,
    post a pic of the stat face for model and type, and of the stat base,
    known to beat dead horses
  • zvalve
    zvalve Member Posts: 83
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