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honeywell aquastat relay doesnt have ZC or ZR...

Just installed a Crown oil fired boiler, was hoping for a direct replacement with all of the wiring, but i was wrong. The new boilers aquastat does not have terminals for ZC/ZR. The old aquastat had them. What do i do with these wires?


  • Oradaps
    Oradaps Member Posts: 11
    this is what im dealing with

    my eyes went crossed after about 5 minutes.
  • billtwocase
    billtwocase Member Posts: 2,385

    What model aquastat? Most OEM supplied controls have been minus ZR/ZC for years. You will need to purchase one that has it. 
  • icesailor
    icesailor Member Posts: 7,265

    That looks like Gas. Gas boilers without a tankless don't use or need ZC/ZR connections. They are there to stop the boiler from getting cold when cold incoming water occurs.

    I've never seen a modern oil fired boiler that has a control like that one. Even System 2000's don't look like that one.

    But can be educated.
  • Oradaps
    Oradaps Member Posts: 11

    Sorry I didn't specify on the picture, that is the control box for all of the zones, the aquastatis an L7224, which apperenlty is obsolete, the old boiler had a coil for DHW, the new boiler does not. On the old aquastat, there were no connections made to the thermostat terminals. So I'm not sure what will tell the new boiler to turn on.
  • Mac_R
    Mac_R Member Posts: 117

    Depending on your application you might be able to get rid of that rats nest and use a Teckmar or Honeywell AQ control.  Both of those controls will simplify your wiring and save the customer money with outdoor reset.  
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