PLEASE HELP! Zanussi ZDV12002FA Cutting-Out

[Lewr1407]

Zanussi Dishwasher
Model: ZDV12002FA
PCN: 91107900603

Hi all,

I’m in need of some help please…..

My Zanussi ZDV12002FA (slimline) dishwasher is cutting-out during the warm-wash cycle. The issue was first noticed about two weeks ago where after a supposed completed wash, the dishwasher was opened and water was sitting in the basin. The dishwasher is 7 years old. I initially thought it may have been a drain pump issue/water intake v/v.

Following a long investigation and stripping everything down, I eventually found a ‘relay’ type noise emanating from the main PCB. It occurs during the warm wash cycle only as follows – the ‘clicks’ occur, the dishwasher cuts-out + power-off, shuts down the pump motor – – relay noise again – power will come back on and pump motor will start back up momentarily to resume cycle – – relay noise again and cut-off and so on. It will do this for a few minutes and then just seem to give up (machine completely cut-out).
With the dishwasher cut-off from own accord, I’ll leave standing for 10 mins and then I’ll be able to power on with the interface ‘on button’ and then the dishwasher will complete cycle, but sometimes I think it repeats some cycles – not 100{e5d1b7155a01ef1f3b9c9968eaba33524ee81600d00d4be2b4d93ac2e58cec2d}.
The user interface/wash selection lights will also come on and off in line with machine powering up and then off with the PCB noise.

The PCB is located at the rear of the machine at the bottom.

Things I have checked/changed:

– Checked continuity on drain pump = all ok
– Checked all lines and hoses = all ok
– Checked continuity on door latch switch = all ok
– Replaced water inlet v/v with new as I originally misdiagnosed the clicking from the PCB for the water inlet v/v solenoid = all ok
– Replaced pump capacitor as I mistook the pump starting/stopping for a dodgy capacitor = all ok
– Checked continuity on water heater = all ok
– Replaced circulation pump with new as I thought this may be on its way out and perhaps short in motor windings causing the cut-out = new part and motor all ok (old motor was fine as cut-out still occurs)
– Mains voltage to machine throughout is good @ 240V so no issue there
– Checked continuity on float switch = all ok
– Cleaned up all basin door seals + filters
– Checked for blockages throughout the entire system = all ok

I disassembled the PCB from the machine, but saw nothing obvious. Difficult to inspect as it’s a closed unit.

I’m not sure what to do now, but I’m thinking the next thing to check would be the thermostat. I think this is integrated into the turbidity sensor. As said before, the heater works fine and hot water is present during the cycle + continuity of heater within measurements.
Perhaps a dodgy thermostat is causing too much heat to come from the heater motor and PCB is cutting the power-off as a result. Would explain the ‘cool-off’ period when everything will work fine again after 10 minutes??

Failing this, it must be the PCB. The only other thing to check would the pressure/overfilling sensor.

Please help!

Thank you so much in advance.

Ps. I have videos of the issue – could I post?

[electrofix]

have you tried a different socket ?

Dave

[Lewr1407]

Hi Dave,

Thank you for your response – much appreciated.

No I haven’t, reason being, I measured the mains supply into the PCB from the power cable and it was a steady 240V during the dishwasher working and dishwasher cut-out.
I also checked the mains supply + fuse at the wall socket – all good.

[electrofix]

I would say it a high likleyhood of a faulty board

could be the board power supply which could be repaired

Dave

[Lewr1407]

Thanks Dave. Would you recommend the PCB be sent away for specialist repair?

[electrofix]

could be worth a try

Dave

[Lewr1407]

Hi Dave,

Do you know what the ohm reading of a turbidity + temperature sensor should be at room temperature?

Zanussi sensor in question:

https://www.espares.co.uk/product/es1737068?utm_source=google+shopping&utm_medium=shopping&utm_campaign=google+shopping&gclid=CjwKCAiA3L6PBhBvEiwAINlJ9EUl-7WzJZLe2KDRu9L46oz9cX7Ux50oYrHQCVbicHaDwVQZDWnKgRoCW1gQAvD_BwE

At room temperature, I’m getting high resistance readings (18500 ohms or at 20k setting = 18.56).

However, the resistance does reduce when presented to a heat source.

[electrofix]

depends what room temp is

its rated 4836 ohm 25 degrees C

cant see it being that as it would throw a fault code vup if anything like that failed

still more likely to be board power supply as these can restart if you turn off and on again

Dave

[Lewr1407]

Hi Dave,

Thank you for that.

I really am at a loss now; I had the PCB repaired, but the same cut-out 5-10 mins into the warm cycle as per video occurs. I was informed that the PCB was faulty and fully repaired, but I need to seek clarification as to what was fixed.

The only other thing I can think of would be the power on/off button via the user interface circuit board. When pressed on/off in quick succession, this creates the same clicking/relay noise. Perhaps heat from the machine and steam due to fatigued seals is creating a short somewhere on the board? I’m really not sure, but just a thought.

It’s just very confusing as it only occurs during the first 10 mins of the heat cycle.

Temperature sensor @ 20 degrees Celsius = 18500 ohms

Lewys

[electrofix]

if there is any kind of bad joint the heater current will find it

you said you checked 240v to the board when the fault occurred. If yes it cant be a power problem as power is still on board when it fails

Dave

[Lewr1407]

Thanks Dave, I’ll keep digging! I really appreciate your time and help 🙂

[electrofix]

if it was me at this point i would check the top board for the 5V supply it needs to work before and after it cuts out

Dave

[Lewr1407]

Ok thanks Dave

[Author]

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