Zanussi dishwasher ZDT24004FA – constantly filling

[muzungu]

HI all, first post here.

My Zanussi won’t stop filling. I have tested the voltage to the inlet valve and it is constantly 240v no matter what setting I have the machine on or whether or not it is on a cycle. Even with the door open it still continues to fill as the valve doesn’t shut off.

If I pull the supply wires off feeding the inlet valve (I’ve taken the side off) the water stops, as one would expect so it’s not the inlet valve.

I have removed the level sensor and cleaned it but still continues to fill, although I would have thought with the door open it should have an interlock so it stops the flow, but it doesn’t.

What happened prior to this was that I had it on the hottest wash, which I usually never do, may be just a coincidence. It then flooded, I am assuming because of the constant fill, and triggered the flood micro switch on the base. I cleared the water out of the base, reset the machine and now constant flow and the 240v to the inlet valve constant.

Any ideas what fault could cause the triggering voltage to the valve never to switch off? PCB fault maybe? I have reseated every connector in the machine including those to the PCBs.

[electrofix]

sounds like a board fault. the valve is fed live and the board switches neutral through a device on the board called a triac. Its likely this component is faulty

Dave

[muzungu]

electrofix wrote:sounds like a board fault. the valve is fed live and the board switches neutral through a device on the board called a triac. Its likely this component is faulty

Dave

Thanks, for that Dave. I was coming round to that conclusion as I have tried just about everything else. All sensors taken out and cleaned, all connectors reseated but whatever I do to the machine I have 240v to the inlet valve until I switch it off at the plug. Even with everything disconnected from the board, apart from the input voltage and the output to the valve, still 240v.

Can’t find a board for this one online so am now looking at the single price repair from Zanussi. Given the price of the boards for other models the single price cost of £145 is not much more than a new board. Must be a catch?

[electrofix]

or if you can solder you can replace the triac

Dave

[muzungu]

electrofix wrote:or if you can solder you can replace the triac

Dave

Yes, was thinking of that, I have the kit. Pretty handy with a soldering iron and small components, a bit of industrial experience. I’ll have to mug up on testing triacs and then see if I can narrow down which one it is.

If I can find an obvious fault, and also if I can figure out how to test them first, I will attempt myself.

[electrofix]

plug E on the board . connections 5 and 6 should feed the valve. Trace connection 5 should take you to the triac

hope this is correct but there are at least 10 machines with same model

Dave

[muzungu]

electrofix wrote:plug E on the board . connections 5 and 6 should feed the valve. Trace connection 5 should take you to the triac

hope this is correct but there are at least 10 machines with same model

Dave

Can’t thank you enough. I’ll get the board out tomorrow and crack on, or try to at least! Thanks again.

[muzungu]

Just to update this. Got the board out and looked at the triac feeding the valve, I compared resistances between pins on this triac with the other triacs along side it of the same type; the one feeding the valve has about 3k between the centre pin and each of the outside pins (forgive the non technical language!) whilst the others are open circuit on the same pins. I am assuming therefore that your diagnosis is correct, given my rudimentary electronics knowledge 🙂

I don’t have the kit to change a surface mount component so it looks like a new board which pains me, not because of the cost but chucking something with possibly just a cheap component. May look around and see if I can find someone to do it for me though.

The other alternatives is to get Zanussi to do a fixed price repair, £145; or to buy a new board which I am having trouble locating, you may know a source?

[electrofix]

all you need is a soldering iron and some de soldering braid, the components are cheap

what have you got to lose the boards scrap

look on utube someone will have done a video

Dave

[muzungu]

electrofix wrote:all you need is a soldering iron and some de soldering braid, the components are cheap

what have you got to lose the boards scrap

look on utube someone will have done a video

Dave

I will be attempting a repair myself, as you say what’s to lose and the component is only a couple of pounds.

Just out of interest I can’t seem to find this board anywhere. Doesn’t seem to exist as a spare part. The only one I have found is a secondhand one on Ebay in France, with the same numbers on the board as mine although advertised as Electrolux (realise Electrolux are also Zanussi).

[electrofix]

electrolux is the parent company but do be fooled, it might be the same board but could have different software so may not work

to look up board availability i would need the complete Pnc number and serial no

Dave

[muzungu]

electrofix wrote:electrolux is the parent company but do be fooled, it might be the same board but could have different software so may not work

to look up board availability i would need the complete Pnc number and serial no

Dave

Thanks for that Dave,

PNC 911 535 206 02
Ser No.94135803

I have put in queries to Zanussi and two major online spares sites, nobody has got back to me as yet. It is more out of interest if my repair doesn’t work out, I ordered a couple of the triacs this morning for a couple of pounds only.

If you have any other way I could look the board up I would be very grateful.

Thanks for you advice,
Chris.

[electrofix]

part no of configured board

97391153 52 06-02 / 4

https://shop.zanussi.co.uk/c/configured-electronic-pb150/p/973911535206024

Dave

[muzungu]

electrofix wrote:part no of configured board

97391153 52 06-02 / 4

https://shop.zanussi.co.uk/c/configured-electronic-pb150/p/973911535206024

Dave

I am an idiot! I just found it as well while I was waiting on the line to the parts department.

You’ve been a great help Dave, can’t thank you enough for your time and being free with your expertise.

[muzungu]

Just to update this.

Replaced the Triac (did a neat job though I say it myself) and no change, still 240v on the pin outs to the valve on the board.

Completely removed the board and all its connectors apart from the supply, so no connection with any hardware in the dishwasher. Still 240v on the valve connectors directly on the board.

I am therefore concluding that there must either a component issue before the triac or the logic has been corrupted in some way? It would seem extremely unlikely the 240v would be the default output to the inlet valve with nothing connected to the board other than supply voltage. Unfortunately this is now beyond my skill level so it looks as though a new board is the way to go which is irritating as it is probably something minor somewhere on the board.

So £136 for a new board which I can fit (surely must be that?) or £146 for a “fixed price” repair from Zanussi.

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