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Boiler Coil- Pex loop issue

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aal2023
aal2023 Member Posts: 8
Have two zones of heat in my house. One boiler with radiators and steam heat on the 1st floor, works great. Had construction done built a second floor. Contractor put in a pex loop on the second floor with baseboards. There is a coil in the one boiler, along with a circulator pump and expansion tank that is used to get hot water to the pex/baseboards and heat the second floor. My plumbing company tells me the only way to turn the heat off on the second floor is to turn the boiler off. It is always hot on the 2nd floor, 80 degrees in some rooms and it is driving me crazy. Is what they are saying accurate? any suggestions on how to resolve this issue. Appreciate any help, thanks

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  • EdTheHeaterMan
    EdTheHeaterMan Member Posts: 8,117
    edited November 2023
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    There is a way to control any other zone with a thermostat and a relay

    Can you post a picture of the boiler, the coil and the circulator pump that connects to the second floor baseboard loop?

    Edward Young Retired

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

  • aal2023
    aal2023 Member Posts: 8
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  • aal2023
    aal2023 Member Posts: 8
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    Sorry the boiler space it tight cant really get a shot of the coil. The circulator is mounted on the wall on the left, thanks
  • Jamie Hall
    Jamie Hall Member Posts: 23,447
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    Control the pump as has been said with a thermostat and a relay. I'd use a dedicated 24 volt transformer, a plain vanilla thermostat, an RIB to switch the pump on command from the thermostat, and stop right there. Easy. Should take a competent person only a few hours, unless running the wire to the thermostat was difficult.

    And your plumbing company is clueless. Which leads me to wonder what else might be wrong...
    Br. Jamie, osb
    Building superintendent/caretaker, 7200 sq. ft. historic house museum with dependencies in New England
  • EdTheHeaterMan
    EdTheHeaterMan Member Posts: 8,117
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    OK. this is the way to get that to work.
    ..


    There needs to be a thermostat for the baseboard zone. That thermostat should operate the circulator pump with a switching relay like a R845A or a SR501

    Then the Switching relay has a separate set of contacts that will go in series with the L4006A high limit that is places by the tankless coil, then on to the burner circuit. When the baseboard heat calls, the circulator will operate and the burner will operate until the burner gets the water hot enough to shut of the boiler by way of the L4006A limit control. This way the burner will not make steam to heat the rest of the house.

    when the baseboard thermostat is satisfied the circulator and burner will stop.

    When the steam radiator thermostat calls for heat, the boiler will make steam and the circulator will not operate, so the baseboard rooms will not overheat.


    Edward Young Retired

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

  • aal2023
    aal2023 Member Posts: 8
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    I Have a thermostat on the second floor for it. The issue is the heat is on regardless. For example right now the baseboards in my bedroom on the second floor are warm even though the temperature is 78 degrees in the room with the thermostat set to 72. It doesnt seem to matter what temperature i set the thermostat to except for the first time the heat is turned on for the season.
  • Teemok
    Teemok Member, Email Confirmation Posts: 511
    edited November 2023
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    Once you can control the pump, dual checks might be needed to prevent thermos-siphoning. There might be a check already in the pump so just a spring check on the supply. That pump is pushing down right?
  • aal2023
    aal2023 Member Posts: 8
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    Appreciate the feedback. To clarify, the steam zone is fine functioning as expected. Right now my boiler is not firing yet the baseboards on the second floor are hot and the temperature gauge i posted on the boiler is at 90 degrees. I dont get why/how the baseboards are hot under these circumstances. Appreciate the image that does help me understand things a bit more. Regarding the spring question i am not sure to be honest. Thanks
  • EdTheHeaterMan
    EdTheHeaterMan Member Posts: 8,117
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    I BELIEVE YOU WILL NEED AN ADDITIONAL CONTROL
    The switching relay that operates the circulator. I do not see one in any of your pictures. If you add the switching relay in order to control the circulator, that should do the trick.

    Edward Young Retired

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

  • EdTheHeaterMan
    EdTheHeaterMan Member Posts: 8,117
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    aal2023 said:

    I Have a thermostat on the second floor for it. The issue is the heat is on regardless. For example right now the baseboards in my bedroom on the second floor are warm even though the temperature is 78 degrees in the room with the thermostat set to 72. It doesnt seem to matter what temperature i set the thermostat to except for the first time the heat is turned on for the season.

    What is that thermostat connected to?

    Edward Young Retired

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

  • aal2023
    aal2023 Member Posts: 8
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    Thanks. I believe the thermostat is “allegedly” connected to a relay, although i am not sure how to confirm this. There is wiring from the second floor thermostat down to the boiler that was run when the thermostat was installed. 
  • EdTheHeaterMan
    EdTheHeaterMan Member Posts: 8,117
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    aal2023 said:

    Thanks. I believe the thermostat is “allegedly” connected to a relay, although i am not sure how to confirm this. There is wiring from the second floor thermostat down to the boiler that was run when the thermostat was installed. 

    Can you identify that wire in the basement? if yes... then take a picture of what the wire connects to.

    Edward Young Retired

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

  • aal2023
    aal2023 Member Posts: 8
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    will try to thank you
  • EdTheHeaterMan
    EdTheHeaterMan Member Posts: 8,117
    edited November 2023
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    Heading to bed. can you confirm my assumptions. Will look for your answer in the morning

    Edward Young Retired

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

    PC7060
  • Teemok
    Teemok Member, Email Confirmation Posts: 511
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    If the thermostat and logically the pump has been off for a long while and the pipe in the baseboard is hot it is likely a thermosiphon problem and checks will fix it. Ed will sort ya out.
    EdTheHeaterManrick in Alaskaaal2023
  • EdTheHeaterMan
    EdTheHeaterMan Member Posts: 8,117
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    Teemok said:

    If the thermostat and logically the pump has been off for a long while and the pipe in the baseboard is hot it is likely a thermosiphon problem and checks will fix it. Ed will sort ya out.

    If you already have the correct wiring and control logic in place, then thermosiphoning is the likely problem. Lets see if the wiring is correct then go from there.

    If it is thermosiphoning, then this part will fix it. https://www.supplyhouse.com/Taco-0010-025RP-IFC-Replacement-Kit-for-Select-Taco-00-Series-Cartridge-Circulators

    Edward Young Retired

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

  • aal2023
    aal2023 Member Posts: 8
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    Sorry for the delay i found the honeywell relay. the grey wire going into it is the same grey i see up by the second floor thermostat