Dishwasher solenoid clicking

[charlie275]

Hi all,

I have a 5-yr old Hotpoint FDW80 which has until today provided near faultless service (apart from a split hose a couple of years ago).

I came back to it after it had completed a wash cycle to find it making what at first sounded like electrical arcing , but later deduced the noise to be either a solenoid clicking or something rattling (actually sounds like it's tapping out rapid morse code ).

It was also showing an AL code but unfortunately I did not take note of this because my instant reaction was to turn the damn thing off quick! but I think it could have been AL05.

Turning it back on cleared the AL code, but the solenoid is still clicking randomly and I can hear a pump going. This is with the machine "off cycle", i.e. I can cycle through the programs on the display. However it only happens with the door closed.

The noise seems to be coming from, or under (above if the machine was right way up), the black part as marked up in photo 1 below. The short stub on the side is also rotating slowly and constantly, except it stutters when the clicking happens (see vid).

Also there is definitely a motor running because I can hear it. I didn't get to putting a meter on anything yet but if I hold a magnetised screwdriver to the drain pump the screwdriver vibrates so I reckon that it could be the drain pump I can hear.

After taking the pics below and put the cover back on and the machine back upright, the noise is still there but the display is now dead. Update: it was switched off, doh! Although it shows that the clicking/rattling noise happens regardless whether the machine is On or Off via the front panel.

I'm hoping with the above description someone can help me diagnose the problem, or ask me the right questions to lead me to it.

Also if water could have got onto the circuit board(s) how can I access these without destroying the machine? - I assume the electronics must be held within the door (?).

Click HERE and HERE for video clips with audio.

Untitled

• charlie275
• 2 Jul 2011
• 1

Untitled

• charlie275
• 2 Jul 2011
• 1

Untitled

• charlie275
• 2 Jul 2011
• 1

Untitled

• charlie275
• 2 Jul 2011
• 1

 

[zipper]

It sounds like you may have a piece of glass in your pump. Take the pump off & have a peek.

 

[charlie275]

Hi, just an update to say I traced the problem and this is now fixed. I'm writing this up in case it is of interest and to link to another thread with information which helped fix the problem.

The black part (shown in pics in my first post) where the noise was coming from is actually the "lower wash arm valve".

I removed the cover and there appeared to be nothing wrong with the mechanism. However it turned out that the main control board was "leaking" voltage onto the motor which is why it continued to turn even with the dishwasher turned off via the front panel.

Normally when the control board wants to stop the motor it should take the centre terminal to 0V and the unit will then "click off" at the next position due to the motor contact opening. However as can be seen in the video HERE this wasn't happening correctly. The control board was supplying a constant 20V to the centre terminal and this is just enough to keep it going. It's a 240V motor and the lower voltage causes it to stutter making the rattling sound that can be heard.

Anyway the problem was traced to a faulty "Triac" on the main control board. Replacing the faulty Triac fixed the problem. Cost of part: 20p !!

Now I know this probably isn't something your average DIYer is going to want to attempt. Soldering tiny surface mount parts is fiddly and requires some skill. Please also be aware that the main circuit board carries 240V mains voltage and can kill you! However if one knows someone into electronics, or even a friendly TV repair shop, then it could save the cost of a new board.

The triacs control the following circuits (left to right):

Wash pump motor
Lower wash arm valve *
Drain pump
Salt valve
Water intake valve
Detergent door release

* this is the triac I had to replace, and shown removed in the photos.

More details in the post here: http://jdesbonnet.blogspot.com/2011/01/hotpoint-aquarius-fdw60-dishwasher.html

Video clip HERE.

Untitled

• charlie275
• 2 Jul 2011
• 1

Untitled

• charlie275
• 9 Jul 2011
• 1

Untitled

• charlie275
• 9 Jul 2011
• 2

Untitled

• charlie275
• 9 Jul 2011
• 1

Untitled

• charlie275
• 9 Jul 2011
• 1

Untitled

• charlie275
• 9 Jul 2011
• 1