Ideal Classic Boiler cutting out

[chasemaguire]

Hi guys,

My boiler is cutting out after approx 30 seconds of firing up, regardless of heating the water or rads.
The closest rad in the system begins to get warm slightly before the boiler cuts out.
I thought the pump might be at fault causing the boiler to overheat and cut out, but the pipes either side of it are hot so presume its ok, am I right to think that?
Any advice is appreciated.

 

[ChrisR]

A jammed pump will heat itself (a lot) and also the pipes connected to it. Try feeling pipes a metre or two away.
It you change the speeds on the pump, you should hear it change speed and/or stop in between settings. Silence = jammed pump.

 

[chasemaguire]

Thanks for the reply, really appreciate it.
If the pump is knackered, does that mean it is jammed/closed?
Can it be opened manually, what is the large screw on the front for?

 

[chasemaguire]

its a grundfos 15-50 by the way

 

[namsag]

Take the silver screw out the centre of pump and see if the shaft under it is spinning