Someone (who ought to have known better in IMHO) decided in the design
that unlike all other modern boilers which have a permanent live and
switched (demand) live connections the BB
would work like an older style boiler with a simple apply-mains-and-it'll-
start design.

The boiler tries to work out when there is little flow and cut the pump
and gas for a while but of course it can't do any pump over-run to remove
excess heat if it stops in full flight.

I blindly followed the manual but thinking about it, and what you point out,
would it seem better to run the pump all the time anyway? Otherwise when the
boiler stops al the water just sits in each rad cooling at its own rate and
nothing will then happen until the boilers own water cools and it decides to
burn again. We have an always-on rad anyway that is capable of being the
by-pass.

I'm gonna check with Baxi techs anyway but an I daft in my thinking (which
would not surprise me!) ?