On 17/12/2019 19:33, Theo wrote:
John wrote:
I thought door locks tended to be mechanical - locked by a bimetal device
with a heating element. Could that heater get too hot if in the proximity
of a tub of hot water?

TV news had a shot of the door lock mechanism (square hole for the door
latch to go through), showing a couple of wires going into it and burning of
the plastic next to one.

Suggested workaround is to wash at 20C, suggesting the heater element isn't
in circuit.

Perhaps they're putting the door lock in series with the heating element?

Looking at the interlocks on ebay, most of them have connectors rather than
wire-terminals. This is from one of the affected models:
http://siteassets.ransomspares.co.uk...6242617757.jpg

Googling for schematics (not that many are public) does suggest it's common
to put the door/lid switch in series with everything else, so the machine is
cut off when the door is open. Which would mean the door switch takes
substantial load on warm washes.

Theo


I wonder if it's more insidious than that, IIIRC there's some Ecobollox
directive that says that appliances must not consume more than 0.5W
when "off". Ours does this via the main (wash selector) switch turning
off the SMPSU, maybe switching through the door switch is just a much
cheaper way of doing it? I notice the door switch referred to in the
pic claims to be rated at 16A...