Boiler pump wiring question

[Someone]

Hi,

We have a Baxi Barcelona which according to the blurb has two ways to connect the pump, one for fully TRV'd systems and the other when used with a bypass. The fully TRV'd one runs the pump from a separate connection from the boiler so that the pump shuts off when the boiler does - the other way being to run it as normal via the timer feed to the boiler.

But running it in this way makes the pump stop when the boiler is not firing, even when the mains to the boiler is on. Is that normal? I thought pumps usually ran all the time.

Thanks.

[Ed Sirett]

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.

You can make of this what you will, of course.

[Someone]

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!) ?

[Ed Sirett]

You are not daft who ever designed Barcelonas should have stayed home that day.