matstand wrote:
I have a cracked toilet cistern which needs replacing. I am a barely
competant DIYer and try and avoid plumbing. I've had a look in B&Q and
could only find complete loos for sale.

can you buy spare cisterns, or is it better to prelace the whole loo.

If it's a close-couple suite where the cistern sits directly onto the
pan you may have trouble finding a cistern that fits (and it's not too
easy taking the pan along to the shops to match it up :-)

If it's a 'low-level' suite with the cistern hung on the wall and
connected by an L-shaped pipe to the pan then any cistern that fits[1]
will do.

Get one with an internal overflow[2]: the new cistern's pipework is
bound not to match up with the old one's and this'll make your life
easier by one bit of pipe at least. Fit a screwdriver-operated service
isolation vale to the cold supply to the cistern, and use plastic pipe
or a flexible connector for the last few inches to the inlet valve
connector.

And hang it with stainless stell or brass screws so they don't rust.

and is it a job for a novice or should I bite the bullet and find a
plumber?

Novice to plumbing or to DIY? If you're OK with drilling holes and
fixing things and genrally solving the sort of problems that come up in
the real world (as opposed to daytime TV makeover programmes :-) you
should find it OK. If you get stuck you can always use a bucket[3] until
you find someone to help you.

[1] it ought to be capable of delivering the right amount of water to
the pan, which is usually set by the flush valve, though the modern
push-button valves often don't have any adjustment. Modern WCs are
required to use 6 litres of water whereas the older ones used 7 or 9
litres. (The fact that many modern ones require 2 or 3 flushes to clear
no 2s and therefore use more water than the old ones seems to have
escaped the wit of the powers that be.)

[2] if/when the inlet valve leaks water will overflow down the flush
pipe into the WC pan rather than through the overflow pipe outside.

[3] to flush the pan with, not to ... oh well I suppose you could use it
for that if needs be