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Controlling 9 Zones on radiant system

BJonesNYC1 Member Posts: 5
Hello and thank you all so much. I learn a tremendous amount from reading your posts and answers. And everyone is always generous and gracious. Hoping you can help me again. I have warm board radiant flooring over three floors in a NYC brownstone. Three zones per floor. Each floor has a manifold. Each of the 9 zones is monitored by a temperature sensor installed above the light switch in the room. The temperature sensors all are connected to 9 Control4 thermostats in a central location. A Triangle Tube Prestige Solo condensing boiler is the source, feeding a Triangle Tube Indirect Fired Water Heater. A Taco SR506-EXP is the switching relay. All worked well for 8 years. No problems until this heating season. The middle bank of thermostats (Zones 4-6) would drain the batteries in a day. Taking those rooms off line, the second floor) No similar issues on other zones or floors. I would like to move away from battery powered thermostats. Is there a nine zone controller that can accept the info from the sensors and call for heat in the 9 separate zones? Or do I have to wire 9 thermostats for power off a transformer? Thank you.


  • Jamie Hall
    Jamie Hall Member Posts: 21,503
    The first question I would have when I encounter something like this: specifically, two banks of controls behave normally, the third, supposedly more or less identical, drains its batteries in a day is...

    Where is the drain draw on that bank coming from? I would start this by trying to isolate the draw. You have it down to one bank -- zones 4 through 6 -- now can you narrow it further to one controller in that bank? Do all three controllers have independent batteries? And all three drain? Is one of the controllers always "on" and shouldn't be? To do the diagnosis I'd really have to be there with a low range ammeter, but you may be able to find the problem just by disconnecting things.
    Br. Jamie, osb
    Building superintendent/caretaker, 7200 sq. ft. historic house museum with dependencies in New England
  • BJonesNYC1
    BJonesNYC1 Member Posts: 5
    Thanks Jamie. Yes, all three thermostats have separate batteries. And I have turned off 2 out of three and other configigurations, always with the same result.
  • Jamie Hall
    Jamie Hall Member Posts: 21,503
    And all three thermostats on that one zone always drain their batteries, but none of the other thermostats do? What is common to that one set, not shared by the other two?
    Br. Jamie, osb
    Building superintendent/caretaker, 7200 sq. ft. historic house museum with dependencies in New England
  • EdTheHeaterMan
    EdTheHeaterMan Member Posts: 6,019
    edited June 2022
    I have always tried to use "Known Good" parts to eliminate other problems. In your case, remove 3 good thermostats and place them aside. Take the 3 thermostats that have the battery problem and install them on the 3 zones that have no problem, with fresh batteries each. Then place the 3 good thermostats on the 3 problem zones. Now operate as usual and see if the problem stays with the thermostats or stays with the zones.

    I have one observation: You show 9 thermostats and you specify they are connected to "A Taco SR506 EXP". By my interpretation of English Language grammar, it sounds like only one relay that can handle 6 zone pumps. Now 9 thermostats with a single 6 zone relay makes me wonder what is missing?

    Another thing is, you have a picture of several low voltage actuators on a manifold. So there may be different controls that are in play that are not described. I'm thinking that at least one of the circulator pumps may operate by way of a zone valve switching control that operates one of the circulators on the SR506.

    Do you have a wiring diagram of the "AS BUILT" control system?

    If not, perhaps a few pictures of the other electrical components can help to diagnose the problem.

    Edward F Young. Retired HVAC ContractorSpecialized in Residential Oil Burner and Hydronics
  • Zman
    Zman Member Posts: 7,466
    Are you positive that the batteries are dead or does replacing the battery just solve the problem? A voltage meter would answer that question.

    It is just a thought, but I wonder if you (or a neighbor) might have a new source of RF interference like a microwave oven or other wireless device that is interfering with the signal. When you swap the battery you reset communication and it works for a while.

    3 separate sensors that all have a short circuit big enough to drain a battery in a day seems really improbable.
    "If you can't explain it simply, you don't understand it well enough"
    Albert Einstein