Hotpoint dishwasher F02

[WindyBoy]

Hi

The background to this question is that I am a mechanical engineer investigating a flood from a brand new Hotpoint dishwasher for an insurance company. The machine is not going to be put back into service, this is just about understanding what might have caused the problem.

The user installed the machine and ran a test cycle. All fine. He left it switched on a tthe wall but off at the control panel. Then he went out. Came back later and there was water coming out at the sides of the door and the code ‘F02’ was on the display.

The Service manual for dishwashers with this type of controller (PLP2) says that F02 means ‘fill valve admits water even when deactivated’.

I have recovered and tested the machine and it worked fine. I have no reason to doubt the person who installed it, but I am struggling to see how the solenoid fill vavle could be opened while the machine was switched off (although on at the 13A wall socket) without the fault being permanent. My knowledge of electronics is sketchy but it stretches as far as knowing that the solenoid is energised via a triac. I’ve googled around, but most of what I’ve read says that if a triac short circuits, that’s it. Time for a new triac. It wouldn’t be an intermittent or one-off fault. Any thoughts?

Thanks for your time.

[iadom]

Re: Hotpoint dishwasher F02

Although very rare on a new machine it is possible for the solenoid valve to stick open, even intermittently. That would be a more likely cause rather than an electronic problem.

[iadom]

Re: Hotpoint dishwasher F02

The clue is in the fault description you posted, ‘admits water EVEN WHEN DEACTIVATED’.

[WindyBoy]

Re: Hotpoint dishwasher F02

Thank you for your replies. Both appreciated.

I wondered about the ‘deactivation’ part of the error code description but I wasn’t sure how the controller was actually monitoring this. If it just assumes deactivation on the basis that that it hasn’t sent an activation signal, I thought that it might be possible for a problem on the low voltage side of the triac to energise the 240V circuit to the solenoid without the controller being aware. Obviously if it’s monitoring the 240V circuit that wouldn’t be the case.

[iadom]

Re: Hotpoint dishwasher F02

The error code is generated as soon as the polystyrene overfill float is triggered in the base.
Obviously if the machine was not plugged in then it would just flood without any error code showing.

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