Has my boiler system been configured wrong?

[redconker]

Hello,

My central heating system is fairly old and has been modified a few times. Right now I have a sealed, pressurised system with a single pump and two motorised valves controlling the hot water and central heating. The boiler is a traditional floor standing unit about 10 years old. It's not a combi.

The motorised valves were put in by British Gas last year replacing two pumps (one for each - CH and Water).

I am wondering if the system has been setup correctly as when the time clock turns both the heating and water off and closes the valves, boiling water is sitting in the boiler and pump runs for upto 40mins trying to move it - which of course it cant.

Should there be another pipe allowing a trickle, bypassing the valves, controlled by a tap to allow the boiler to cool down? If so, should this be plumbed into either of the feeds to the CH or HT after the valve?

Or, does this matter? Is it okay for the hot water to sit in the boiler and for the pump to run for 40 mins?

Thanks for any help you can offer.

 

[Agile]

Sounds like they did not fit the auto bypass valve which they should have done!

Not a massive job though.

Boiler make and model?

Tony

 

[dcawkwell]

Sounds like they replaced two pumps to achieve nothing.

 

[redconker]

Thanks Guys / I have a kingfisher MF

 

[xr4x4]

If the pump and boiler are still running after the timer has gone off, it has been wired wrong.

It shouldn't.

The pump should still run for a few minutes with a bypass to stop the boiler boiling but as it's unlikely your boiler will have this, that wont work anyway.

The motorised valves should turn the boiler and pump off.

I don't understand why it's running for 40 minutes..?!

 

[Agile]

Surely that boiler has a pump over run and runs it for so long now because there is no circulation because of the missing auto bypass valve?

Tony