On 09/04/2018 19:13, Johnny B Good wrote:
On Sunday afternoon, when looking in our basement for some (250mL)
15W-40 engine oil to prep up a 1K2W inverter genset I'd bought from our
local Lidl for 99 quid a couple of hours earlier, I discovered the coal
hole section had become somewhat flooded and threatening to flood the
main part of the basement.

snipped

[1] Although I'm rather loath to dig out my sump standpipe, if needs
must, I would but, of the bunch of potential 'submersible' pumps on page
121 of the Toolstation catalogue, it worries me a little as to what the
description "Not suitable... for permanent installation." implies about
each and every one of these pumps. Do they mean, "Don't chop the 13A plug
off and wire into an FCU." or does it mean they're simply not able to
withstand being sat in a puddle of water indefinitely in between pumping
sessions?


A small 12 volt boat bilge pump would go down your existing 75 mm sump
pipe. I guess you could suspend it either above or below the "steady
state" water level. Then have it switched on by a suitable float switch.

Also, there are plenty of cheap "damp" alarms on ebay, I've just bought
one to fit into a friend's condensate drain to give him early audible
warning of a frozen outlet.