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Tekmar demand signal with TRV's

I was just wondering what guys are doing to signal a demand through a Tekmar or similar boiler control with a system using TRV's or where end switch wires cannot practically be run to the control.

We've thought of using a flow switch but have had trouble finding one with a low enough minimum flow to close the switch. This is for small multi-family units consisting of 4-6 zones.

Since we run conventional oil fired boilers we have to maintain much higher temps than necessary in the shoulder seasons. Our thoughts are with a proper demand signal we could run it on a cold start. Systems are set up primary-secondary with the system loop using a delta-P Wilo Stratus Eco pump so flow rates can get quite low.


  • SWEI
    SWEI Member Posts: 7,356
    TRVs modulate

    So flows really can get down there.

    Given the requirements, I'd probably install an ORC-controlled mixing valve on the distribution loop and let the WIlo run all the time (it will go to sleep in the event the TRVs all close off.) Then add a buffer tank and use WWSD on the burner.
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