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Thermostat and taco zone not controlling temperature

Byronguzhnay7
Byronguzhnay7 Member Posts: 12
edited December 2 in Thermostats and Controls

Good evening everyone

I need you help with my burnham series 2 boiler

I have to zones in my house, both are 3 wire taco zone valve and 2 new thermosthat that I recently replaced but the problem is that both of them are not controlling the temperature for each zone , the valves open Eben with the thermostat off and it gets too hot

Comments

  • neilc
    neilc Member Posts: 2,854
    edited December 2

    what kind of thermostats ?

    were they? and are they?

    pictures of wiring ?

    known to beat dead horses
  • Byronguzhnay7
    Byronguzhnay7 Member Posts: 12

    Horizontal Non-Programmable Thermostat

  • Byronguzhnay7
    Byronguzhnay7 Member Posts: 12

    One thermostat is in the second floor and the other one in living room that controls the first floor and basement

  • EdTheHeaterMan
    EdTheHeaterMan Member Posts: 9,401

    Did the old thermostat s work properly?

    A model number or picture of the old thermostats will help.

    also the model number or picture of the new thermostats too

    Edward Young Retired

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

  • Byronguzhnay7
    Byronguzhnay7 Member Posts: 12

    Will take pictures of the wiring

  • EdTheHeaterMan
    EdTheHeaterMan Member Posts: 9,401

    How about pictures of the thermostats that you are having a problem with too

    Edward Young Retired

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

  • Byronguzhnay7
    Byronguzhnay7 Member Posts: 12

    The old thermostats did work just fine , everything started after I install the burnham series 2, everything works fine , only the 2 thermostats and the 2 zones don't control the temperature, the boiler it does pro ide heat and the pump works as well

  • neilc
    neilc Member Posts: 2,854

    are the zone valves stuck in manual open?

    pictures there also

    known to beat dead horses
  • Byronguzhnay7
    Byronguzhnay7 Member Posts: 12

    The zone open and stay open

    The other zone I have to open manually

  • EdTheHeaterMan
    EdTheHeaterMan Member Posts: 9,401

    "The zone open and stay open." I read this as: The thermostat will open the zone valve once and the zone valve never closes after that. Is that what you mean?

    "The other zone I have to open manually". I read this as: The other zone valve does not open by the thermostat at all. Is that correct?

    Did you do the zone valve , and the boiler wiring or was this done by a contractor that can't get it right?

    Edward Young Retired

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

  • Byronguzhnay7
    Byronguzhnay7 Member Posts: 12

    Yes correct , zone open with thermostat and stays open

    The other zone does not open with thermostat

    I did the boiler and the wiring

  • Byronguzhnay7
    Byronguzhnay7 Member Posts: 12
  • pedmec
    pedmec Member Posts: 1,067

    its 78 degrees and 73 degrees in the rooms. How hot do you want it???

  • EdTheHeaterMan
    EdTheHeaterMan Member Posts: 9,401
    edited December 2

    It is hard to tell where the wires go from your picture but I will give it a try

    You can do a taco zone valve in several ways. and you can also get the R and the W backwards on most thermostats you can also get the R and C on the transformer backwards and it might still work. But I have found that this particular zone valve ALWAYS works if you follow this diagram in this exact order.

    • R from zone valve transformer to R on each thermostat
    • W from each thermostat to 1 on the corresponding zone valve motor
    • 2 from all the zone valve motors go to C on the zone valve transformer. 
    • Finally All the #2 terminals from all the zone valves go to T on the boiler control
    • And all the #3 from all the zone valve motors go to the other T on the boiler control  

    It appears that you have done that, but I can’t see all the wires in your photograph so I would verify with a meter that the zone valve that is stuck open has ~24 VAC on #1 and #2 terminals on the zone valve motor when there is a call for heat.  When the call for heat is over there should be no voltage at all on terminal #1 and #2 on the zone valve motor.  If the call for heat is over and you still have ~24VAC on #1 and #2, then you have something wired incorrectly.


    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: 9,401
    edited December 2

    Where does this wire go to?

    Never mind… that is the wire that goes to the boiler control T T

    Edward Young Retired

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

  • Byronguzhnay7
    Byronguzhnay7 Member Posts: 12
    edited December 10

    Good evening

    Update

    I did check all the wiring and the 2 zones heads , everything seems to be in good right and the zones in good condition but the zone 2 it opens even if the set temperature is very low, and remains open

    Zone 1 , I have 25 v at the thermostat but it does not open

  • Byronguzhnay7
    Byronguzhnay7 Member Posts: 12
  • Jamie Hall
    Jamie Hall Member Posts: 24,876

    You're making headway. At this point, I'd be interested in the behaviour of the two zone valves, and especially the voltage difference between the two connections for the zone valve actuator: the centre connection and the connection to the thermostat. When the thermostat is calling for heat, you should have 24 volts AC — or very close to it — across those two connection points. When the thermostat is not calling for heat, you could get almost any voltage reading. I'm thinking that one or both of your thermostats aren't working properly — or that there are problems with the wiring.

    Br. Jamie, osb
    Building superintendent/caretaker, 7200 sq. ft. historic house museum with dependencies in New England
  • neilc
    neilc Member Posts: 2,854

    is that left actuator leaning, not mounted properly, maybe binding the valve stem,

    are the levers up, and not down in manual position?

    known to beat dead horses
  • EdTheHeaterMan
    EdTheHeaterMan Member Posts: 9,401
    edited December 10

    I need to do this step by step.  The first step is to set the thermostat to call for heat on one of the zone thermostats.  Then with a meter check to see if the corresponding zone valve has 24 volts at terminal #1 and terminal #2 on the zone valve.  If yes  then the valve should open,  That valve can take up to 2.5 minutes to fully open.  Once the valve is fully open, the boiler should operate the circulator pump and the burner should operate up to the high limit temperature.  

    Confirm that it works properly.  If you do not get 24 volts at #1 and #2 on the zone valve, then you have some wiring wrong.  If you have 24 volts at #1 and #2 on the zone valve and the valve does not open, then you have a defective valve motor.  

    Assuming that you have a working valve and you get heat to the room, turn the thermostat down below the room temperature.  Measure the voltage at #1 and #2 on the zone valve. You should get zero voltage reading.  If you still have 24 volts at #1 and #2 on the zone valve, then your wiring is not correct.  If you have zero volt at #1 and #2 on the zone valve and the valve does not close, then the manual lever is set to open, or you have a defective valve body.  Replace the valve body in that case.

    After you complete the wiring diagnosis on the one zone valve, you can do the same test on the other valve.   This testing may take about an hour or more since the taco valve action is slow.  Once you have completed each step and you still haven't found the problem, click on the spoiler here

    Once you have completed each step and you still haven't found the problem, I would suggest that you stop wasting time on the zone valve wires and get a taco ZVC 403.  This control will put all the wires in the correct place and eliminate any confusion.  Remove all the wires from the zone valves and have the following wires connect to the ZVC 403. 

    Connect 120 VAC to the ZVC 403 as indicated in the instructions

    Connect X X from the isolated end switch to the boiler T T connection.

    Connect zone 1 thermostat R W wire to zone 1 thermostat terminals R W in the control

    Connect zone 2 thermostat R W wire to zone 2 thermostat terminals R W in the control

    Connect zone 1 zone valve 1,2,and 3 to zone one 1,2,and 3 terminals in the control

    Connect zone 2 zone valve 1,2,and 3 to zone two 1,2,and 3 terminals in the control

    Power up the control and the boiler.

    The green light will indicate that there is power to the control and that there is 24 volts available to operate the valves

    On a call for heat from zone 1 thermostat a yellow lamp will indicate there is a call for heat from zone 1 thermostat

    Once the valve opens completely the red lamp will indicate the valve is open and the boiler will operate.

    Same procedure for zone 2

    When the call for heat is satisfied, the red and yellow lamps will go off.

    Edward Young Retired

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