So my single zone ufh is set up as a separate zone where a T87RF room stat is setup as the sensor and a BDR91 is paired as the actuator. The BDR91 in turn switches a motorised zone valve on, which previously was also firing up the boiler. The ufh zone has it's own flow and return branch from the boiler before the CH motorised zone valve. Because the evohome doesn't deal with S Plan+ it was previously configured as an S plan. So everytime the ufh had heat demand the CH valve also would get opened.
Today i moved away from using the CH valve controlled by evohome. It's now permanently kept open. Boiler is fired by the Opentherm bridge.
What I have noticed today, although it may have always happened is the ufh bdr91 keeps turning on an off even if the set point hasn't been reached. I would have expected the zone valve to stay open until set point is reached and then may be at the set point keep going on and off to maintain the set point, or better still let the OT bridge regulate the temperature.
So why does the bdr91 keep going on and off even below the set point? Is it TPI doing this?
Today i moved away from using the CH valve controlled by evohome. It's now permanently kept open. Boiler is fired by the Opentherm bridge.
What I have noticed today, although it may have always happened is the ufh bdr91 keeps turning on an off even if the set point hasn't been reached. I would have expected the zone valve to stay open until set point is reached and then may be at the set point keep going on and off to maintain the set point, or better still let the OT bridge regulate the temperature.
So why does the bdr91 keep going on and off even below the set point? Is it TPI doing this?
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