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Zone Valves wont automatically...Help greatly appreciated

ebrady07
ebrady07 Member Posts: 10


So I am dealing with a Tarm furnace from 1987. My dad has been having some memory issues and decided he needed to replace most of the motors on the zone valves. In the process he screwed up all the wiring. I followed a wiring guide I found online and at least got the pump working for the forced water baseboards but none of the valves are turning on or off via the thermostats...you have to manually open and close them. Luckily temps in Ohio are not too cold but that won't last long. I tried using a multimeter to figure out the hot lines but I'm really not a expert at this. The wire with the blue tape goes to the aquastat. If any heating genius out there could please take a look at my wiring attempt and tell me what I am not doing right I would REALLLLLYY appreciate it...so would my mom. Thanks

Comments

  • mattmia2
    mattmia2 Member Posts: 7,207
    There are a lot of different ways to wire these depending on how they are powered.

    Where do the zone valves get their power? Where do the end switches connect on the boiler?
  • ebrady07
    ebrady07 Member Posts: 10
    That is one of my main questions too...there are just the wires coming down that are taped to the pipes...they look just like all the other wires but a couple definitely have more juice to them than the others. Whoever put this together really didn't care about labeling anything. I followed the diagram on the hot wire I found with the multimeter and put it where I think it should go but I'm not sure if there is one that comes on the left side too.
  • ebrady07
    ebrady07 Member Posts: 10
    edited November 2022
    The only thing that connects to the boiler is the one with the blue tape that goes to the aquastat...all the others just go directly up to the rafters and I assume thermostats
  • mattmia2
    mattmia2 Member Posts: 7,207
    Are there only 2 wires going to the boiler? Do they connect to t t on that control?

  • ebrady07
    ebrady07 Member Posts: 10
    The two the go to the boiler/aquastat are connected to the end switch terminals
  • hot_rod
    hot_rod Member Posts: 18,268
    edited November 2022
    It looks like about 8 wires coming from somewhere. Could be each valve had a wire from the thermostat and a separate wire for the end switch to turn the pump on

    The wood boiler may not have a TT, it runs via its own temperature control, and there may be a buffer tank also?
    Bob "hot rod" Rohr
    trainer for Caleffi NA
    Living the hydronic dream
  • mattmia2
    mattmia2 Member Posts: 7,207
    Where are they connected at the boiler? T-T? If so the end switches should all be wired in parallel and connected to T-T so that if any of the end switches closes that will make a call for the boiler to heat and circulator to run. That should be completely separate from the thermostats and valve control.

    There should be a transformer somewhere to power the zone valves. It may be in the ceiling somewhere.

    One side of the transformer should be connected to one side of the motor of all of the zone valves.

    The other side of the transformer should be connected to one side of the thermostat. I think there is a screw on the zone valve that isn't connected to anything internally for this splice.

    The side of the thermostat that isn't connected to the transformer should connect to the end of the zone valve motor that isn't connected to the transformer.

    A lot of that wiring is just jumpers to parallel the end switches and to connect power from the transformer to each valve and thermostat.
  • ebrady07
    ebrady07 Member Posts: 10
    I can get a pic of the side of the furnace when I get home....its basically just the transformer with a on off switch then that goes to the aquastat relay box which is connected to the aquastat by two wires
  • ebrady07
    ebrady07 Member Posts: 10
    I know nothing has been removed...the way its strung together is how it always used to work until my dad goofed them up
  • 109A_5
    109A_5 Member Posts: 484
    Hello @ebrady07,

    Assuming you wired it all up correctly, I would verify 24 VAC between TH-TR and TR is present all the time (Red dot to Orange dot in picture) on all the Zone valves. If 24 VAC is not present go back to the appropriate transformer and see if there is 24 VAC there, if not check the 120 VAC input to the transformer. With the chaos, the transformer(s) used to power the Zone Valves may have been damaged or just shut off at some other point.

    If the 24 VAC is correct between TH-TR and TR, set at least one thermostat for a call for heat and then you should have 24 VAC between TH and TR (Blue dot to Orange dot in picture) and the Zone Valve motor should open the valve for that zone.



    National - U.S. Gas Boiler 45+ Years Old
    Steam 300 SQ. FT. - EDR 347
    One Pipe System
  • HomerJSmith
    HomerJSmith Member Posts: 1,927
    edited November 2022
    How many thermostats do you have? Any WiFi thermostats? Aquastats transformers are usually limited in the number of zone valves (3) on the circuit. Do you have an auxiliary transformer providing power? Five Zone valves calls for five thermostats.
    What is the model of your aquastat?

    The green circles on the ZVs are correctly wired. The red circle on the ZV is incorrectly wired, I think. Those connections are for the END SWITCH. The end switch connect to the boiler aquastat at the TT or TV/T or Z connections. It is this switch that turns on the boiler thru the aquastat and turns on the pump. The only power that goes to the end switches comes from the aquastat transformer (ZVs can be wired for an auxillary transformer, tho). The 2 conductor cable that comes from the aquastat one wire from the TV connection should be connected to the TH/TR screw. Then one thermostat wire should be connected to the TH/TR screw. Then a wire from one end switch screw goes to the TH/TR screw, too. Then the other wire from the aquastat T connection goes to the other end switch screw. The other thermostat wire should be connected to the TH screw. The other wire from the aquastat Z connection should be connected to the TR screw. Your photo shows the End Switch going to the TR connection. How it is wired depends upon an auxiliary transformer and type of aquastat. All the ZVs should be wired in parallel.





  • mattmia2
    mattmia2 Member Posts: 7,207
    It is hard to tell form the picture, but it does appear that the end switches are wired correctly. There are some wires that run parallel that make it looks like one of the power wires for the zone valves connects to and end switch.

    It looks like the power for the zone valves comes in on the thinner tstat wire on the second from left pipe which crosses over and connects to the furthest left zone valve and the other zone valves are powered from jumpers off of that valve.

    What kind of thermostats are on this? Does the second from left zone have a smart thermostat or setback thermostat or some other sort of powered thermostat? It looks like there are 2 cables going to that valve ans maybe one of those is not wired correctly.
  • mattmia2
    mattmia2 Member Posts: 7,207
    There may be 2 transformer connections bringing power down along the second form left pipe. There looks like there is a connection between the bottom right terminal on the center and center right zone valve that is not connected.

    You need to follow back all 3 of the cables on the second from left pipe. One or possibly 2 will go up in a wall to the thermostat but the other or possibly 2 will go to a transformer.