In an earlier contribution to this discussion,
Andrew Gabriel wrote:

You will need to allow for pump overrun with most boilers.
The Honeywell schematic does not.


This is true. In fact, it's only a small change from the Honeywell diagram.
The basic logic remains the same, but the output from the zone valves'
volt-free contacts drives just the boiler rather than the boiler and pump in
parallel. The pump is then connected to the boiler's pump control terminal -
which is live whenever the boiler is firing plus whenever the boiler's pump
over-run stat calls for circulation to continue.
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Cheers,
Set Square
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