Washer-dryer: "anti-flooding system"

[Adam Funk]

The washer-dryer stopped working this morning & displayed an error code for which the manual says, "Anti-flooding system has activated. Disconnect the appliance and contact the service centre."

There's no sign of water leakage anywhere; the towels had gone through the filling & heating-up stages, but not been fully washed. The machine is still under warranty, but I'm curious as to how an "anti-flooding system" works, & whether the technician is just going to press a secret "reset" button tomorrow.

[Andrew Gabriel]

I've seen two technologies referred to as flood prevention:

A large tray across the bottom of the system with a float in the middle, which catches any leaks, and the float triggers an emergency shutdown, which abandons the cycle and pumps out the water. Reset in this case consists of draining the water out of the tray using sponges or tipping the machine, so the float drops back to normal position. (Don't tip the machine to empty the tray unless you are sure you aren't tipping the water into something electrical.) If the machine is left unused for some time after leaking, the tray can dry up by itself, but crud left behind if the water was dirty can prevent the float dropping down by itself.

Logic which detects water level dropping unexpectedly, or which detects the machine taking too long to fill. No reset required in this case - just restart the machine.

I expect there's a variety of different systems in different manufacturers' machines.

[Harry Bloomfield]

Andrew Gabriel was thinking very hard :

Which might be due to low water pressure.

[Andrew Gabriel]

Which is one reason why machines specify a minimum pressure (another being that the electric water valves used in them require a minimum pressure to reliably shut off).

[John Rumm]

One of the Miele ones has a hose within a hose and an electrically operated stop valve at the tap end of the hose. So if the hose springs a leak it is contained, and also triggers the shut off valve.

[Andrew Gabriel]

That seems to be quite common. Seem some Whirlpools like this too, and if something leaks into the outer hose, it runs back into the bottom flood tray, triggering the float.

[Andy Champ]

Our dishwasher did this for a pinprick leak. Annoyingly I couldn't fix the damn leak on a polythene thingy (1), and had to buy a new bit. Of course I can say that here, as the unreasonably expensive bit was less than half a call out charge :)

Andy

(1) Anyone know a glue that will stick to polythene in the presence of hot dishwasher detergent? If you do, please don't tell me...

[SteveW]

One which I have seen on a dishwasher is a microswitch held closed by a sponge. If the sponge gets wet it softens and allows the switch to open. In this case, the sponge had gradually deformed under the pressure of the microswitch over the years. Simply reversing the sponge solved the problem for the rest of the life of the dishwasher.

SteveW

[fred]

Rigid plastic structure? Drill through the pinhole and seal with a rubber washer under the head of a setscrew inside, washer & nut outside.

[Adam Funk]

That's the one. The technician found enough water in the bottom to trip the float, but couldn't make it leak. (There are some secret ctrl-alt-F1-type combinations that do diagnostic things like spin as fast as possible with water running in.) He thinks I put too much detergent in on the 95° cycle & filled the drum with foam so the rinse water overflowed from the inlet.

[Andy Champ]

Concertina pipe.

Andy

[fred]

Not a chance then, nothing will stick to something that slippery and flexible so replacement really was your only choice.