CH smart pumps

[Stephen]

Hello,

I have a Wilo smart CH pump and I am unsure if I need a bypass valve if I am using the smart pump. Without a bypass valve, wouldn't the pump automatically adjust as TRVs close? But if I added a bypass valve, wouldn't that open and cause the pump to run at full throttle at all times? Surely that defeats the object of having a smart pump?

The boiler manufacturer says I do not need pump overrun so I do not need a bypass valve for that.

As it happens, there are rads without TRVs (next to the thermostats) so wouldn't these allow sufficient bypass?

I appreciate that one day someone else might replace these non-TRV'ed rads with TRVs or close them off whilst decorating so perhaps a bypass would help future proof against this but I'm still concerned it would defeat the purpose of having a smart pump?

Thanks, Stephen.

[Ed Sirett]

You system needs a bypass if the boiler needs it. In general that will be when there are S-plan controls (2 x 2-port valves.)

A smart bypass will only openb when needed.