Worcestor Heatslave 20/25 reset problem

[peterraikman]

When asked for hot water or heating, my boiler runs for about 6 minutes then stops and has to be reset. ( the little black button )
The power light is on
I can hear the pump running
The Lockout light is off
The green switch is set to hot water
The two water heat setting knobs are set to medium
It was serviced this summer

Anyone got any ideas ?

 

[Agile]

Merely listening to the pump indicates nothing much!


Suppose the impeller had fallen off?

Or the eye of the impeller was totally blocked?

Or a pump valve was closed?

Or a pump valve was blocked?

Or there is no water in the system?


The thing to do is feel the temperature of the pipes connecting to the boiler.

The return should start to warm up after 2-3 minutes.

Tony

 

[peterraikman]

The pipe which is second from the left at the top rear ( marked " to rear of appliance, with an arrow pointing backwards gets very hot quite soon, and stays hot. After a while the boiler will fire once again if I press reset.
In the morning it fires once of its own accord. None of these priduces anything more than tepid water.

 

[stumpydick]

check pressure guage above burner shows 1 bar,if not find filling loop and restore primary pressure.

 

[Boilerman2]

Sounds like either faulty pump or air trapped in the boiler, (there are two or three manual air vents on top of these boilers)