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Zone Valves

Bill_4 Member Posts: 16
Ive got to add another transformer to a system as there are already 3 zone valves, wont tying in another transformer overload the sysyem a blow out a transformer? These are 3 wire Taco valves and Ive already blown one, you have no choice but to tie them together at the TT terminals, I mean if one transformer puts out 24 volts. wont another 24 volts.
screw things up? Bill


  • [Deleted User]
    Could he just

    Replace the transformer to a 24 volt 75VA????I know taco says no more than 3 valves on a 24 volt 40 VA transformer?Am I correct?????
  • Floyd
    Floyd Member Posts: 429
    The 75 va looks like....

    the best option... you should be able to handle at least 5 and maybe 6 zones with that.
    Get one with a built in curcuit breaker they are only a couple of bucks more and if you
    screw up all you have to do is reset it.

  • Dale
    Dale Member Posts: 1,317
    Using 2 transformers

    is what I would do, if you look at the taco installation instructions they'll show how to test to make sure the 2 transformers are in phase and not bucking or trying to give you 48 volts. I like to use a cheap 3 amp circuit breaker as a jumper when I do this, is the breaker opens you have a short or major overload. The 75VA trmr is another way to go but most guys don't have one as truck stock.
  • Alan(CaliforniaRadiant)Forbes

    (as well as many others) makes a zone valve controller that will have the correct VA output for the number of attached zone valves. The have them for 1,3,4,5 and 6 zones, with diagnostic lights (great for troubleshooting) and some have hot water priority.

    If you buy the -EXP zone valve controllers, you can add more zones plus have outdoor reset (boiler reset or injection) and they aslo have some cool plug-in modules for indirect water heater post-purge timer, pump exercise, etc.

    All very cool.

    To Learn More About This Contractor, Click Here to Visit Their Ad in "Find A Contractor"
  • Bill_4
    Bill_4 Member Posts: 16
    zone valve wiring

    Hey! Can anyone PLEASE tell me how to wire 4 taco valves with 2 transformers! Thanks,Bill
  • Mr. Bill
    Mr. Bill Member Posts: 71
    2 Transformers

    Bill, the trick is the wiring of the transformers not the zone valves.

    You need to join 2 transformers in paralell and treat them as 1. Use 2 equally rated transformers and join them as shown. You will end up with twice the current capability but still only 24 Volts.

    Hook em up wrong and you'll have 48 volts and a puff of smoke!
  • jeff_25
    jeff_25 Member Posts: 110

    a cheaper why to fuse is get 3 amp flate fuse like carrier use on there boards (car fuse) and couple of insulated spade terminals lot cheaper than inline fuse holders and circiut breaker
  • I have a manual available on Zone Valves

    and how they should be wired it answers all of these questions. From some of the answers posted it is apparent that many of you do not understand transformer phasing. I also recommend that you get familiar with NEMA (National Electrical Manufacturers Association) Class II Transformers Standard DC 20-92. This standard establishes how transformers can be operated at 200% of capacity with a voltage maintained between 20 to 23 volts AC without damage to equipment or transformer.

    One solution to the transformer phasing problem is to wire 3 Taco Zone Valves to one 40 VA transformer, and each set of three to have a seperately wired 40 VA transformer. By not parallel connecting the secondarys you avoid problems.

    I agree with using the new circuit breaker transformers. That way if you have a short circuit in the secondary wiring you will not burn out the transformer.

    A 75 VA NEMA Rated transformer can easily handle 6 TACO zone valves.
  • Ingvar
    Ingvar Member Posts: 5
    it won't work that way!

    hooking up two transformers in parallel will not split the load equally. Since the internal resistances of the two transformers are not exactly equal the transformer with the lower resistance will still supply almost all of the current while the other transformer loafs. You can test this by feeling the transformers and seeing that one of them is much hotter than the other one.
  • bb
    bb Member Posts: 99
    in the future...

    ... you could look at the Danfoss Zone Valves. Since they only consume 2VA up to 12 can be used on a 40 VA transformer.

  • Bill_4
    Bill_4 Member Posts: 16
    Thermostat Problems

    Hey, Ive got a customer complaining that the new Honeywell
    thermostat I installed is malfunctioning.Its one of the round ones and whats happening is,he sets it at 70',it comes on at 64' and goes off at 68',any suggestions?? thanks
  • Boilerpro
    Boilerpro Member Posts: 410
    Not level or incorrect anticipator setting

    Anticipator setting based on type of system. Gravity hot water (and converted with pump)/ steam, 2 times current draw; forced hot water baseboard, 1.4; scorched air 1 time. I'd expect most radiant systems would be like gravity water/steam

  • Factors for setting Thermostats

    Dave I believe those settings are for special situations. When I was with Honeywell the 1.4 factor was for mid efficiency and high efficiency systems including forced warm air and forced hot water. They are designed to change the cycles per hour for systems from 6 cycles per hour at 50% of heating load to 3 cycles per hour. This was necessary to insure proper operation of these systems. The engineering people at Honeywell advised that setting systems arbitrarly at those settings was not a good idea. They should be used in systems that the cycling was affecting operation.

    This factor of 1.4 would work this way:

    Normal amp draw of primary control .4 x 1.4 = .56

    This would put less false heat on the bimetal in thermostat causing it to run longer therefore less cycles per hour.

    We would often set anticpators on converted systems to.8 to give proper cycle. It was also necessary on some converted steam systems to set the pressuretrol to 3lbs off 1lb on in order to get steam to the third floor on those converted systems. I know this is contrary to what Dan teaches but many of our steam systems in the inner city of Providence would not work properly with out setting the pressuretrol that high.
  • chris smith_2
    chris smith_2 Member Posts: 37
    zone valves

    i use a couple of thease relays i stock them on my truck they cost about $13.00 each., that way i can just stay with standard transformers and such, they also have a light for on/off, and look nice


    chris smith

    paradise porter maine
  • Mcquade
    Mcquade Member Posts: 1
    valve controller problems

    Have  a 6  valve with a water heater tank  zone running off 1 boiler, The controller is a thin add on as you need with 4 zones per board. The transformer is connected to the the first with a 4 amp fuse the others as you go down have 2 amp fuses.  The 4 amp fuse is the only one in turn shutting everything down. How can I isolate the problem? Is there a sequence in which I should check first?  Should I check valve loop or boiler loop first? I need to determine what to change first.

    The transformer seemed to have proper voltage, around 26- 27 amps. System runs a while and is pain burns fuses when I am gone.  Can anyone help me with this??
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