Hotpoint WDUD 9640 tripped fuse box during drying cycle. Filled machine with water and gave F15 error code.

[sagatr]

Hi everyone. My Hotpoint WDUD 9640 washer dryer suddenly died during drying cycle. It started to fill the washing machine water and tripped the main fuse box. 
 

After turning on the fuse I switched the machine on again but it immediately gives error F15 and starts filling washing machine with water. You can not switch washing off at that point as all buttons stops responding. I had to turn off the power and manually drain all the water out. I tested for blocked pipe, lint filter, and water pump. They are all ok. I also tested the heating element of both washer and dryer. The resistance On those also appears to be ok.

I decided to take out the main control module as the F15 error was suppose to be caused by faulty relay. I found 3 relays are not working as expected. Please see The attached image. The relay on the top had shorted coils. The next one down had correct coil resistance of 400 ohms. But energising the coils did not effect switch position. The relay at the bottom had short on both on / off position.

I desoldered all the relays as I thought they were faulty. However they all work as expected out side the circuit.

Does anyone have any idea what could be causing these issues?

I know I can get replacement board but the new ones will cost £179 + coding card etc which will be over £300. I am trying to find the exact board that came out from WDUD 9640 on eBay. So far no luck. I can find the exact board for around £30 but obviously has different firmware. Does anyone know which chip stores the firmware so may be I can swap the eprom chip from my board to a similar eBay board so I don’t have to program it.

Any help would be appreciated. 

[Whitegoodshelp (Andy)]

Hello there. Unfortunately the white goods industry has never repaired PCBs. It's one of the incredibly wasteful practices that has brought us to our current throwaway society problem. So no white goods engineer is likely to be much help because they are only expected to replace the entire unit. As you have pointed out the price of these printed circuit boards is ludicrously expensive.

Funny enough the most popular thread so far and these washing machine forums has been one about repairing the PCB on another brand of washing machine where someone outside the white goods repair industry who understands a fair bit about electronic acts and PCBs called Bob12241 described how he very cheaply and quickly fixed his own washing machine by just replacing one capacitor. So you should find this thread interesting, although it is not going to directly help you if by any chance Bob could answer your question on this thread it is your best chance of getting help here.

[Whitegoodshelp (Andy)]

If not, then the only other help I can point you towards is to try QER electronics who repair PCBs for white goods appliances.

[sagatr]

Thanks for the reply.

I have done futher testing to find out what could have tripped the main fuse box. I read the resistance of the dryer heating element which is showing 503 kilo ohms. The normal reading should be around 10 - 50 ohms. Can someone confirm if this is correct reading for a good element. My reading shows that my dryer heating element is faulty which could have tripped the fuse box.

I know modern washing machine will not turn on correctly if I disconnect the cables from certain parts. In my case the heating element. But can I use a 10 ohms resister in place of the heating element as a dummy load to fool the main module to start up normally. 

This way I can diagnose the issue and identify the faulty parts. 

[Whitegoodshelp (Andy)]

If an element has a very high resistance it’s usually broken inside. It’s possible for a broken element to trip the electrics but to diagnose a fusing or tripping appliance you need an insulation test meter, which is a specialist tool. The electrics usually trip when electricity runs down to earth. 
 

I have some advice on it here Tripping electrics

[sagatr]

I am no longer getting tripping fuse box. It just happened once. So I am assuming it was caused by the dryer heater element. The problem I am having now is immediate F15 error code soon as I switch the machine on. I tried disconnecting the dryer heater element and turning on but still get the same error. Does this mean it is only repeating the last known error as it can not detect the heating element. I just want to fool the main board to think that a heating element is connected to verify that it is causing the error.

[Whitegoodshelp (Andy)]

2 hours ago, sagatr said:

I am no longer getting tripping fuse box. It just happened once. So I am assuming it was caused by the dryer heater element.

Yes that makes total theoretical sense. Sometimes when heating element fails it will trip the electrics but then it will no longer trip and you are just left with the element not working. However, all of the Hotpoint F15 error code descriptions that I have say that F15 means the fault is with dryer heater relay. This takes us back to your initial investigation unless by any chance Hotpoint have changed its meaning on later washing machines as all of my error codes are relatively old now.

I would suspect there is a possibility that if the heating element did, "blow" it could have damaged the dryer heater relay inside the PCB. To be honest, without a proper insulation test meter you can't really test to see if there is low insulation on the dryer element, or anywhere else for that matter. 

This clearly is not a simple DIY job so unless you are very tenacious the odds are against you with this one. You could remove the dryer heater cover and physically inspect the heating element. If it is warped or actually broken then you will at least know what the cause is. However you would need to fit a new element, which usually involves using some special high melting point sealant, and then hope that the fault is fixed.

If the relay has been damaged, which is definitely implicated by the error code then you still have the difficult decision to make because they are very expensive to purchase unless you sent it to QER.

[sagatr]

I have decided to take out the dryer heating element and have a closer look. It seems to be burnt out and has a crack. Multimeter reads 5 mega ohms.

I connected a 47 ohms resister between the two contacts that plug into the heating element as a dummy load.

I switched the machine on and the F15 error is gone. The machine also stopped filling up water. All the buttons on the washing machine started to work normally. I am able to select wash a cycle etc. So I can safely conclude that the F15 error is caused by the faulty dryer heating element.

I have now ordered a replacement dryer heating element that will hopfully resolve my issue.

[Whitegoodshelp (Andy)]

Thanks for the update. Please let us know how you get on so this topic can potentially help may other people. 
 

If replacing the element fixes the issue it will be another example of how unreliable error codes can be. 

[sagatr]

I managed to install a new dryer heater element today. The machine started correctly with no error code. I did a fast wash cycle which run fine. Soon as the wash cycle finished I did a dry cycle. After few 2 mins into the dry cycle the washing machine switched off completely. All the front led lights off etc. 
 

I turned off the main power switch and turned back on again but the machine will not turn on anymore. It’s completely dead.
 

I think the old faulty heating element must have done some damage to the main module. I took out the main module to see if there are anything obvious on circuit board. Nothing seems to be blown. The main voltage regulator chip is LNK625PG. Is there any way I can test this chip to see if it’s dead.

I am now looking for a replacement module or may be send the pcb for repair.
 

I found the exact same module with the same firmware version and date. But it’s for a different model WDAL8640P. Do you think I can use this board as replacement or do they have model specific firmware installed as well.

[Whitegoodshelp (Andy)]

I would guess it would work but couldn't say for certain. If it's expensive I'd consider sending yours to QER

[sagatr]

I sent my module to QER. According to them they found a fault and reparied it. Today I received the module and plugged it into the washing machine. To my dissapointment exactly the same problem. No power or display, no beep nothing. Completely dead.

I can't really tell if they have repaired the board correctly or there is another issue somewhere else. 

Is there a fuse inside the washing machine somewhere that may be blown ? Could there be a fault in the front display module ?

[Whitegoodshelp (Andy)]

Hello there. I would expect that QER would have definitely found something and fixed it. They wouldn't be stupid enough to think they could get away with pretending to fix something that they know very well would not fix the fault once you refitted it. Also, I have seen many cases where people have sent the PCB to QER and they have returned it saying they could find no fault.

With something like this the first thing I would doublecheck is all of the connections to the PCB.  I would go through every plug and if possible very gently prise out the metal connectors inside, and gently tug on the wire to ensure that none are loose. Also I would doublecheck that you have definitely reconnected the correct plugs. Hopefully you took a photo or used some other foolproof method but I have known PCBs be designed so that the connector plugs can be fitted the wrong way round or even into the wrong place as they did not all have unique keys.

Also doublecheck the very basics such as that the fuse in the socket is okay and check any extensions that may be in use. Don't even assume that the wall socket is okay.

 

[sagatr]

All the connections are definately ok. I numbered them and took photos to make sure. I know power is comming to the washing machine and also going to the module. My multimeter has a non contact AC voltage checker. It flashes and beeps if it detects AC power. It detects power on the main wire going into the machine and also on module side. 

 

 

 

[Whitegoodshelp (Andy)]

I would contact QER, tell them what's happened and ask if they have any suggestions or can check it again.

[sagatr]

I have contacted QER asking them if they fully tested the board. They told they cant fully test the board but detected power on the board after they repaired it.

I checked the power coming out from the module socket that connects to the main control display unit. The voltages are fluctuating between 1-2 volts. This is not normal as I would expect it be constant 5v or 12v.

They told me to send it back to them for a second look. I am hoping they can repair it properly this time.

Otherwise I will have to dump the machine. Its a real shame as I cant find a second hand module matching my exact model.

[Whitegoodshelp (Andy)]

Thanks for the update. I suppose it’s impossible for them to test the. Lards out “fully” as they’d need to put it into the correct washing machine. So they must just test individual components and the main power and that usually sorts most things out but not necessarily everything. Fingers crossed. 

[sagatr]

I have got the board back from QER for the second time. They told me they found additional fault and repaired it. Unfortunately the board came back with the same issue. The machine will not power on. I asked QER for a refund as I did not get the service I paid for. They have refunded the money since they had two attempts to repair the board but failed.

I have decided to dump the washing machine as I am unable to get a second hand module to match my machine.

So to conclude this thread. The original F15 error was caused by faulty dryer heating elemement. That also damaged the main module while the fuse box tripped. Replacement heating element got rid of the F15 error and I was able to run a wash cycle. When I tested the dry cycle the machine switched off after 2 mins into the cycle and the main module died.

I beleive that if I could have got hold of a replacement module the machine would have came back to life. I could not wait any longer as the wife was getting impatient.

Thanks you for your help.

[Whitegoodshelp (Andy)]

Many thanks for the update. It’s a shame about the PCB but glad QER refunded your money. 

[Champagnecharly]

I hope you fixed your issue. 

for anybody who has the same. The firmware is held in the daughter/vertical board. Many washing machines have the same base board so swapping the firmware board would work of the rest looks identical. 

To desolder the daughter board I recommend using a hairdryer to warm it up and use some desoldering braid to wick up the solder. 

As for the f15 you had run a thorough test on components. My problem today was simple  the heater live had disconnected from the terminal.