On Tue, 03 Mar 2020 06:35:16 +0000, Stephen wrote:

I only got a second or two before the fuse blew, but I think the noise
came from the pump. Would that make sense?
Yes...

I've read that pumps can
seize. If it was seized, would it stall a draw a higer current than
usual and blow the fuse?

Possibly.

I read that you can unscrew the large screw
onthe shaft of the pump and try to move the pump spindle.

Yes.

The boiler
is an ancient Seme and I know I need to save up and replace it with a
modern condensing boiler. The pump has a bolt head in the centre of
the shaft which I managed to loosen and I could feel the shaft
rotating but some black water came out.

If it was stuck, it isn't now...

I am waiting for some replacement fuses to arrive. I'm wondering
whether the pump was seized and whether I have managed to loosen it.

If it was, it isn't now...

Do you think it is worth taking the pump off to give it a rinse?

No.

I was
surprised the water that came out was so dark as I added inhibitor and
a magnetic filter.

Do you think I should get a new pump just in case? The one fitted is
probably the original and very old.

Depends -- on when you replace the boiler, and the risk of another pump failure.
If the pipes freeze, that's bad, if the house goes a bit cold and you need to
use electric heaters or a woodburner for a while, it's not.


Thomas Prufer