Zanussi tabletop ZDM16301WA overfilling

[Gaji]

Just wondering if anyone can help me troubleshoot an overfilling problem with this machine? I just replaced the float switch as I thought this wld be the culprit but it has just flooded again during initial fill. The water leaks out the bottom of the door and the anti-flood device kicks in & stays on until reset. The next 2 possible options I can think of are faulty inlet valve and / or worn door seal. Am I correct in saying that if it was just a leaky door seal/gasket itself, then that alone wouldn’t set off the anti flood mechanism so more likely to be the inlet valve stuck open? I don’t have a multimeter at hand to test components at the moment. I would welcome any input to troubleshoot as I don’t have much of a clue. I don’t want to spend £300 on another machine if this is fixable. It’s 5 years old & has had no previous issues. Anyone had similar conundrum?

[electrofix]

the fill level of your machine is goverened by a pressure switch
https://www.ebay.co.uk/itm/Electrolux-Pressostat-1509566103-/132069037791

this switch gets air pressure from rising water inside the machine

possible problems

blockages at the bottom through build pu of sludge etc
leak in the hose (less likley in a dishwasher)
pressure switch diaphram damaged leaking air pressure

first off find the switch, remove and blow down the tube to see if its blocked

Dave

[Gaji]

Ah great, another avenue to try before I spend any more money on parts that aren’t required! Much appreciated advice, I will look for the switch & see what state it is in & check tube.

Many thanks Dave

[Gaji]

electrofix wrote:the fill level of your machine is goverened by a pressure switch
https://www.ebay.co.uk/itm/Electrolux-Pressostat-1509566103-/132069037791

this switch gets air pressure from rising water inside the machine

possible problems

blockages at the bottom through build pu of sludge etc
leak in the hose (less likley in a dishwasher)
pressure switch diaphram damaged leaking air pressure

first off find the switch, remove and blow down the tube to see if its blocked

Dave

I found the switch & was able to blow through easily & hear the switch activating each time. No obvious blockages. Couldn’t seem to separate the actual switch to find diaphragm. Fitted all back together and tried a test wash load on 90 minute program – Everything worked perfectly, no overfill or leaks & cycle finished without fault. Next wash a day later on 30m program & the machine overfilled again & leaked out at base of door. Anti flood NOT activating this time.This time also an error code appeared of ‘-10‘ which is something like ‘The appliance does not fill with water’ which seems strange as that’s the opposite of what it seems to be doing. Back at square one after being sure it was fixed. Wondering if it was just the position I had the machine in to dismantle casing that has temporarily unblocked something before reverting back to form. Any ideas?

[electrofix]

you obviously blew into the switch (good job it was an early one as you can destroy the later ones doing that ) but did you blow the other way into the machine?

this fault could be a blockage
or a dirty switch contact
or a very small hole in the switch diaphram

Dave

[Gaji]

I took hose off from switch and blew both into the machine and into the switch – I heard air go through into the chamber and the switch with no indications of blockage in either direction. The switch is the round disc shape variety & I tried to see if I could separate the housing from the terminal half by twisting it and levering with screwdriver as there were no obvious screw fixings to unscrew but I was afraid I would break it so didn’t manage to separate them to see diaphragm. The switch contacts looked clean when I took the connectors off.

[electrofix]

it does sound a bit like there may be an air leak in the pressure circuit. so its either the hose leaking but it could be a hole in the diaphram. try blowing switch till it clicks then get you finger over the end and hold it. see if it leaks out and clickes back

there are 2 switches in this range of dishwashers. Early one has a modded pressure chamber at about £47 later one is about £10 cheaper

problem is its a bit steep to buy on a punt

Dave

[Gaji]

Yes I’d seen the cost of the switch & you are absolutely right it IS a bit steep to buy on a punt as you say. I’ll have another look for an air leak following your instructions.
Many Thanks for your advice, much appreciated the help

Gary

[Author]

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