Whenever I start a program on the WDE12 both inlet valves open allowing water to enter. The problem is that they fail to shut off so the machine just keeps filling with water. This happens even if I use the program to just empty the drum: the machine will pump water out but also allows water in! It would appear that both are working as they will shut off if I reset from the front panel.

I've checked both the pressure switch and tube (by dismantling and blowing) and they seem OK - there is no blockage and the pressure switch clicks on and off when tested.

One other thing: there is a noticeable smell of some component arcing so I checked the connectors to the main board and they all seem clean. No smoke so difficult to tell where the problem lies and no immediate signs of blackening anywhere else.

Simon, November 2008

Thanks for your answer, dannyboy. It was very helpful.

I established that the problem was, indeed, located on the mainboard; once I removed it from its plastic casing (located lower rear of washing machine) I could see where the tracking had overheated causing the board to malfunction.

For anybody else who experiences this problem, there are a couple of replacement mainboards available for this particular machine. Which one you need is determined by the serial number (of the washing machine). The boards don't come with the necessary eprom but, assuming the board you are replacing hasn't gone up in flames you should be able to transfer the existing chip to the new board without problem. If not you will have to purchase one separately. To be on the safe side, remember to earth yourself prior to handling the board or eprom to discharge any static buildup which may adversely effect your new board.

You will need a torx T10 driver head to undo the two screws holding the board casing to the washing machine chassis. The board itself is easily extracted from the housing but you need to make a note of the location of each multipin connector prior to removal so that you put them back in the right order. Also note that, in order to remove the board you will need to detach the connector leading to the drainage pump which lies at the lower front of the machine.

Cost of new board was under £100 (and it arrived within a week) so well worth the effort of exchange.

Simon, November 2008

If the machine has a microprocessor controller it may have an intermediate driver circuit board to control the valves - digital circuitry cant drive mains voltage components such as valves directly. The switching component is called a triac and if its gone open circuit it will open the valves constantly. Trace the valve wiring back and it should lead directly to the switching board which may be what you smell burning out. Some driver boards are separate devices and some are integrated into the main board but separated by devices called optoisolaters. Whatever type it is, the board will need to be replaced.

Repair and service your own washing machine. Go to www.2ndwave.co.uk/manual.html

dannyboy, November 2008