grundfos selectric pump

[doobydoobydo]

Should my grundfos pump get extremely hot. I have a british gas 330 condensing boiler, its NOT a combi. I have a cylindar for storing water and

9 rads. The pipe joined above and below it is also hot so presumably hot water pipe. Brand new boiler, old pump.

Just that I've read before that a hot pump means its not turning.

Thanks

[Andy Hall]

If it's not turning at all then the boiler would be cycling on for short periods and then off and the radiators would not be getting hot.

It's possible that the pump has shorted turns in the motor, because that would cause it to become hot.

Try running the system with pump on and boiler off (e.g. turn off gas supply usually works) and see if the pump still gets very hot.

If it does, then time for a new one.

[doobydoobydo]

okay thanks

Rads do get hot but boiler doesn't stay on for long.

[Andy Hall]

The pump could be running slowly. Is it making a lot of noise and vibrating?

I would run the pump on its own next - I think that that will tell you.

[doobydoobydo]

Are you saying by the way that the pump should not be red hot.

[Andy Hall]

When the boiler is running the pump case will tend eventually to get towards the temperature of the water running through it. If it's getting to similar temperatures with the boiler off and cold water running through, then there's a problem.

[tony sayer]

They do get quite hot and sometimes that depends on whether or not their in the output line from the boiler or the input line before the boiler.

Suppose there some obscure reg covering that somewhere....

[doobydoobydo]

Thanks for answers. It is apparently just the hot water which runs through it that is making it hot, which I guessed it would be. New piping set up to new cyclinder and new boiler. So not used to the set up.