Hello,

I went away for a couple of weeks and I didn't know how cold the house
would get so rather than turn off the heating, I left it set low for
frost protection so I didn't come back to burst pipes. When I got
back, the house was very cold and the boiler was dead. I investigated
with a volt stick and found that current was going to the boiler from
the FCU but no further. I looked on the PCB and there is a 1.6A fuse
that had blown. I didn't have any replacements: the best I had was a
couple of 1A fuses from a shaver socket adaptor. The boiler tries to
start but there is a funny noise and then the fuse blows. It doesn't
help that I was using 1A fuses rather than 1.6A.

I only got a second or two before the fuse blew, but I think the noise
came from the pump. Would that make sense? 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? I read that you can unscrew the large screw
onthe shaft of the pump and try to move the pump spindle. 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.

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

I read that sometimes valves stick when you go on holiday but as this
is a combi boiler and the heating is on one zone, the only valve is
the diverter that switches between CH and HW and since I get neither
CH nor HW, I'm sure the problem lies somewhere else.

Thanks in advance!