Tom wrote:
On 18 Feb, 13:37, Mathew Newton wrote:
On 18 Feb, 10:21, Tom wrote:

(assume pressure switch needs door
sealed)

What do you mean by this? The pressure switch is normally connected
via a pipe to the bottom of the sump. As the machine gradually the
fills the weight of the water compresses the air in this pipe and
eventually activates the pressure switch thus cutting the valve. This
action will work whether the door is closed or not.

I was thinking that if perhaps the overfill detection is achieved via
a two-stage pressure sensor then if your pipe were blocked/damaged
then this would prevent the sensor activating.

Mathew

OK, so that’s how the pressure switch works then. So the device on the
upper left inside of the unit that the water is initially piped
through might not be relevant. Not sure what this does then. Not sure
why water is directed up there first. There are wires to this unit so
the cut off could be in there but linked to a pressure switch in the
pump sump area (cant be anywhere else in this model) which could
easily have got blocked with food/gunge.


Normally the pressure switch is activated by rising water. But if the
pressure tube falls off, it will never activate. The fill is
controlled only by 1 or 2 solenoid valves controlled by the electronic
controller. Usually its pressure switch operation that stops the fill.
There are usually no back up devices, any one failure can cause a
flood. Backups cost extra. Apart from pressure tube blockage or leak,
pressure switch failure and electronics failure, grit in the valve can
also cause it to not shut off.

If its flooded once, trust me, it will almost certainly do it again.
Either put it where it wont cause any harm or replace it.


NT