look in the instructions for the boiler, it will either have an internal bypass or require an external one fitting. However, where an external is required it should already be fitted, but check just in case the installer couldn't read...surprisingly common
If you have a Boiler which does not have a built-in by-pass, you will need to fit an Automatic By-pass (Honeywell) this will need to be connected to the Htg F&R, BEFORE either of the Zone Valves, there will be no need for complicated electrical circuitry to encounter, both valves can close instantly and the pump over-run will use the bypass
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