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Weil Ultra warm weather shut down no domestic hot water

dirtrider180 Member Posts: 1
I have a weil ultra 105 with 1 zone for heat and another zone for the indirect hot water. It was installed in the winter. Now it is getting warmer out when it is over 70 it goes into warm weather shut down as it should as I have the outdoor temp sensor installed. The problem is when the indirect water heater is calling for heat it still doesn't turn on. They are hooked up to a taco controller. Is there a setting I need to change or??


  • Paul48
    Paul48 Member Posts: 4,469

    That's not nearly enough information to even make a guess.Call in a pro to get it straightened out, then educate yourself about how the system works. The guys here can help you with that process, but it's much easier to do when you don't have to worry about no hot water. The knowledge will pay you dividends down the road. Best Wishes.
  • Jean-David Beyer
    Jean-David Beyer Member Posts: 2,666
    when the indirect water heater is calling for heat it still doesn't turn on

    I am not a heating professional.

    I do have a Weil-McLain Ultra 3 80,000 BTU/hour boiler with a W-M 36 gallon indirect (actually Triangle Tube).

    It does not have the problem you are experiencing, so my guess it may be installed incorrectly, or the U-control may be programmed incorrectly.

    Since you have only one heating zone and one connection for the indirect, I have no idea why you have a Taco controller at all.

    If the near boiler piping is done according to the installation manual, the thermostat for the heating zone is connected to the priority 2 thermostat input, and the indirect is connected to the priority 1 thermostat. The heating zone is connected to the system side of a primary-secondary setup (either closely spaced Ts or a low loss header), and the indirect is connected across the supply and return of the boiler after the low water cutoff on the return side and the pressure relief valve on the supply side.

    The U-control should be programmed so that when the priority 1 thermostat calls for heat, only the circulator to the indirect runs, the boiler reset control puts out a constant temperature (190F by default, but I have mine set to 175F).

    When the priority 2 thermostat calls for heat and the priority 1 thermostat is not calling for heat, the boiler circulator in the primary loop runs, and the boiler heats as specified by the priority 2 reset curve, and the system circulator in the secondary loop runs.

    You may wish to read the installation manual to see how it should be installed and programmed. You may also wish to know why a Taco controller was provided, since if the system has only one heating zone and one indirect, I cannot imagine what it is for.
  • Steve Whitbeck
    Steve Whitbeck Member Posts: 669

    Does each loop have a zone valve to control water flow?

    If they do then the zone valve end switch for the indirect must be wired to the indirect terminals on the boiler. These terminals will overide the WWSD.
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