AEG dishwasher F45010W0 code i60

[echase]

I get a i60 code on Auto or Pro 70 programmes but it’s OK on the 30 minute programme. It stops with this code half way through the cycle, probably at the the end of the wash cycle and the start of the drying one.

I put a thermocouple in the inside and it measured 72C during the Pro70 programme so it seemed to be heating alright but I can’t be sure it did not just keep heating and so trip the overheat stat. From monitoring its electricity usage, as in the watts versus time graph below, I see that the element is on permanently, except when changing from prewash to main and a tiny dip after about 40 minutes. Shouldn’t it be cycling on an off more frequently to maintain its set temperature?

I dismantled the temperature sensor and checked all the solder joints and the resistance of its thermistor and all looked well but possibly the resistance of the thermistor has drifted out of value.

I checked it on the 30 min cycle and the temperature kept rising until 50C was reached in the wash phase and it only got to 57C, close to its designed 60C, during the drying phase 2-3 minutes before the cycle end.

Could it be that the overheat stat has drifted a bit low in its temperature trip point so it is tripping even though the actual temperature is correct? Where is this stat as it’s not listed as a part in any parts list I can find? Part of the heater?

Or it the connection between sensor and control board open circuit, which the controller may interpret as temperature being too low so forcing too much heating.

What do I try next please?

[echase]

PS That graph was for a Auto programme. It should carry on working for around 120 minutes but has triggered the i60 code and stopped running after about 45 minutes.

[electrofix]

if sensor was open or short circuit you would get an i70 fault

i60 fault is either a temp above 78 degrees or failing to rise temp when expected. measures temp rise every 3 mins and it must rise by a certain amount each step

check sensor resistance

Dave

[echase]

Many thanks. It is hard to gets the sensor at an exact temperature but by putting a litre of kettle water into the sump with my thermocouple I could get it within about 2 degrees. I then measured at the disconnected control panel end of the wire around 4850 +/-100 ohms at 25C and 1339 at 54C. So seems correct. I am tempted to temporarily add 20-50 ohm in series to fool the controller into thinking a real 55C is apparently around 60C. Then it should shut off the heater before any over temperature trip. But that won’t help if it’s a failure to rise at the right rate. Looks to me like an overheat sensor calibration fault.

I assume the table above is for the resistance at the terminals of the sensor and not at the thermistor. There will be a slight difference as I noted that there is a fixed resistor on the sensor’s PCB in series with the thermistor. E.g. 4850 ohm at 25C looks to me like a standard 4700 ohm thermistor in series with 150 ohm.

[electrofix]

well. its worth a try as an experiment

Dave

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