On 13 Feb 2019 21:49:03 GMT, Bob Eager wrote:

snip

After reset, it'll stay untripped when the machine is powered on at the
socket, but as soon as I turn the control to anything other than 'off'
the RCD trips."

Well, he also said:
"The strange thing is that I've left the washing machine unplugged and yet
the RCD still tripped a couple more times"

Yeahbut that didn't negate the WM from 'the issue' as it was tripping
more regularly when it was connected?

The WM *must* be playing a part, even if it isn't the only player?

I think so too! There is something very marginal, and the WM may have a
minor leak (e.g. heating element).

Agreed (and seems likely from the further info from the OP).

As an aside, we have just ordered and I replaced Mum's washing
machine. Well, it replaced a replacement she was given years earlier
and I found was doomed to fail when I made it functional a bit back.

I was given to her by her granddaughter on the grounds that I might be
able to fix it and I recently did when her (very) old Hoover finally
died (rear ally drum casting corroded away).

The Whirlpool was 'crunchy' when you turned the drum by hand and after
stripping it down, I found *loads* of calcium loose between the drum
and the tub.

However, I also noticed loads of corrosion and cracks in the inner
spider that supported the back of the drum so told Mum not to use the
higher spin speeds (and she wanted to get *some* use out of the WM
because 1) she was given it by her GD and 2) she had stored it for
some time so wanted to use it out of principal. ;-)

The other day she said 'it's leaking and won't spin' and when I went
to pull it out ready for the new one, I turned the drum and found it
really rattling about and the drive belt was broken and on the floor.
;-)

We got her a Bosch like the one our daughter got us as it has one
simple program knob and a stop / start button and ours seems to work
ok (with an A+++ energy rating or summat). ;-)

Cheers, T i m