circulation pump query

[news]

On an S plan system with a gas boiler that has a constant live feed to a boiler over run circuit, in order to keep the circulation pump running to remove residual heat in the boiler, is it normal to control the pump at all times via the boiler? Or does the over run circuit only activate as the boiler stops burning till the boiler is below a set level, with the normal circulation still controlled by the motorised valves?

The boiler in question is a 3 year old 50kW New Ideal, non condensing in the boiler room of a large rambing 4 bedroom house with ballroom.

AJH

[Bob Minchin]

On my fairly new WB, the boiler is always in control of the pump.

Mains in to boiler, demand into boiler, boiler out to pump. I would assume this is logical as only the boiler knows when the heat exchanger has cooled enough to be able to switch off the pump.

[Jonno]

[e-mail] scribbled

That would be called a mansion, verging on being a palace, where I come from.

[ARW]

WB pump overrun is nothing more than a 3 minute timer:-)

[ARW]

Are you sure the circulation pump is not for the HW? This would mean your system has two pumps.

Normally a pump overrun is controlled by the boiler and with an S plan a bypass is used as both valves are closed when the boiler turns off.

[news]

Sorry for delayed reply: it's a big house and there are twin paralleled pipes feeding a 40mm main, these are the only pumps..

For some reason the room stats trigger boiler (which is wrong but something to do with the motor on motor off 40mm Belimo valve not being compatible with the honeywell spring release on the HW circuit) but as most of the rooms have TRVs the pumps can run for long periods while the boiler is not firing. This is why I wondered if I could control the pumps directly from the boiler.

AJH