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Controling thermostat

TonyL
TonyL Member Posts: 6
What could cause one of three thermostats to control the entire system? I have two Ritetemp 8022C programables and 1 Honeywell t87f. The only way to get heat to the programable controlled areas is to have the t87f turned up which then starts the system, then heat goes to the other locations otherwise neither of these two will work on their own.

Comments

  • Ironman
    Ironman Member Posts: 6,440
    Need more info

    What type of system do you have? Forced air? Hydronic? Is there a zone control panel?
    Bob Boan
    You can choose to do what you want, but you cannot choose the consequences.
  • TonyL
    TonyL Member Posts: 6
    the system

    I have a hydronic system, there are 2 ritetemp progammable thermostats model 8022C and one honeywell T87F thermostat.  there are 3 honeywell 8043E zone valves off of one circulator.  another circulator is dedicated to the domestic hot water.  there is is TACO SR502 control and a Honeywell 845A relay. 
  • Charlie from wmass
    Charlie from wmass Member Posts: 4,195
    why not get a 503?

    the 502 is for 2 zones the 503 is for three but you said you had zone valves? the Taco you list is for circulator pump control. I am guessing the other zones were never wired to turn on the boiler and boiler circulator.
    Cost is what you spend , value is what you get.

    cell # 413-841-6726
    https://heatinghelp.com/find-a-contractor/detail/charles-garrity-plumbing-and-heating
  • Ironman
    Ironman Member Posts: 6,440
    edited October 2010
    Agreed

    It sounds like the two other stats are only opening the zone valves. You could also have a bad end switch in the zone valves.



    If this set up is to work right, the end switches should  be wired in series and then back to one set of "T T" terminals in the SR502. But you would have to have a zone valve on each of the three loops with an individual stat on each loop. The other set of "T T" terminals would connect to the aquastat on the indirect. The connections between the stats and the zone valve motors should be separate from the end switch connections and fed from a separate or larger transformer.



    Does the green LED on the SR502 light up? Do any of the red LEDs light when a stat calls fr heat? If not, the fuse or transformer on the SR502 may be bad.
    Bob Boan
    You can choose to do what you want, but you cannot choose the consequences.
  • TonyL
    TonyL Member Posts: 6
    Lights

    the green light and the red lights do come on. 
  • Ironman
    Ironman Member Posts: 6,440
    RED LED

    Does the red led for the zone circ. come on when either one of your "non functioning" stats is calling for heat by itself? If it does, then you probably have a bad circ. pump. If it doesn't, then the zone valve is bad or wired wrong.
    Bob Boan
    You can choose to do what you want, but you cannot choose the consequences.
  • TonyL
    TonyL Member Posts: 6
    lights

    The red light does not come on when the two thermostats are calling for heat.  only comes on when the third thermostat is calling for heat.  
  • Ironman
    Ironman Member Posts: 6,440
    Zone Valve

    Either the zone valves are bad, or their end switches are bad or it's wired wrong.
    Bob Boan
    You can choose to do what you want, but you cannot choose the consequences.
  • TonyL
    TonyL Member Posts: 6
    Thanks

    It looks like the end switch on two 1 year old??? zone valves are bad.  I switched out the zone valve that controlled the others with one of the "bad ones" and the zone worked just fine with all lights as they should be. 

    Thanks Ironman
  • TonyL
    TonyL Member Posts: 6
    not the zone valves!

    After having the zone valves checked by the company that put them in it turns out that they were not the problem.  they NOW work fine.  the problem is the antifreeze in the system apparently gumming up the valves so they would not fully open and activate the end switch.  this only happened to the newest of the zone valves the old one worked fine. 
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