Originally posted by Edinburgh2000
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The heat demand from an HR92 is just an indication of the valve opening percentage, and for a BDR91 it is a duty cycle - a constant heat demand of 30% sent to a BDR91 would turn it on for 3 minutes out of every 10 minutes.
The controller is not commanding every individual turn on/off event - it sends a percentage from time to time and the BDR91 does the cycling itself. (The exception is the hot water relay which is always commanded to 0 or 100% to immediately turn it off or on - there is no TPI modulation of the hot water relay)
So the problem you suggest of the indicators turning on and off constantly doesn't exist - its only the relay that cycles on and off, the heat demand is always a proportional value, which can be reduced down to say 3-4 quadrants for display purposes.
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