Stanley 80k twin series

[Steve11115]

Hi guys, having a problem with 80k series again, the recirculating pump keeps going 4 hours after heating/hot water has been turned of. Is there an overrun stat on these, or somthing else maybe causing the problem.
Thanks for any help

 

[oilhead]

There is pump overrun on these. It is necessary to dissipate the heat from this hunk of cast iron. If you are only using it for hot water at present, then the lag of your cylinder thermostat may not switch off what is a high output burner quickly enough. Is your system a Y or S plan?

 

[Steve11115]

Hi thanks for quick reply. Not sure tbh. If theres no room stat would that be s plan

 

[oilhead]

Not necessarily. Do you have 2 2port valves or 1 3 port valve?

 

[Steve11115]

1 3 port

 

[oilhead]

This is Y plan. If running for hot water only, then you are heating alot of water in the boiler with a high output flame. When the cylinder temperature is reached, the boiler will still be hot, and the only circuit open for the pump is the already hot cylinder, so it takes a long time to lose the excess heat. Try turning down the boiler thermostat a little.

 

[Steve11115]

Cheers for the reply, it goes on for an hour a daybin summer at the momemt, has only started doing it last 3 weeks