Hotpoint WF 840P – The dreaded F-03 Error

[dodders15]

I hope someone may be able to advise the next fault finding step here. I have read all the posted advice on this thermistor system related fault, but still battling to try and diagnose whether the fault is with the thermistor sensor or the controller card.

Symptoms sound quite familiar to other posts. Probglem started as occasional error which could be cleared by total power removal – wait – repower. Now the problem is there at each repower. If I press power on button, get normal power up character test followed by ‘ON’. All looks good but after a few seconds there is a faint relay click, 1 beep and the F-03 error message. At this point the centre placed cold valve starts to feed and the pump also starts. I am believeing this might be a system protective measure in case of over heat, although no such condition exists.

I have measured the thermistor resitance at about 38 KOhms, resistance decreasing when dipped in hot water. Since I do not know what the normal resistance range for this sensor is, I decided to get a little inventive to see how the controller reacted. 💡 I made up a small variable resistor network which I could connect to the controller wiring in place of the sensor. I systematically widened the resistance value above then below the measured 38K to see if I could get back inside an acceptable range. Having tried 10 K all the way up to 400K without any let up in problem,

Although I could mess about and get a new sensor etc, I am now concluding the controller is more likely to be at fault here.

One little clue may be that when I measure the resistance of the sensor whilst still connected to the controller, I see a very much lower resistance of about 5K. Without a circuit diagram for the controller it is a bit difficult to deduce whether this is normal.

I am an electronic engineer, so my instinct is to have a good look at the controller PCB now, for anything obviously amiss. I am sure this board is going to be a fairly expensive item to replace speculatively.

I would appreciate thoughts on whether my fault finding approach is going the right way here. Thanks

[helo_75]

spot on

its usually the board to be honest

and youll need an eprom too

[dodders15]

Re: Hotpoint WF 840P – The dreaded F-03 Error

Thanks for the support and advice helo_75. I have the module out now and the cover off, but nothing obvious to see other than a few flux residues around the underside.

I am a little confused by the comment about the eprom (EEPROM maybe?). This particular card has a 27C64 surface mount EEPROM soldered to th board, with a normal larger 8 pin DIL socket in parallel but unpopulated (circuit ref U8 ).

Are you saying that the purchased spare of the power/control module will always come without an EEPROM, and this additional device must also be fitted to the PCB by the repairer before use? Will this still be the case if the module is ordered specifically for the WF840P from the Hotpoint spares organisation?

Sorry if these questions are a bit searching, but the devil is always in the detail with these type of jobs 😈 !

[helo_75]

nope, the boards are quite often used on numerous machines, the eprom is the differnce…. the new board comes with a surface mounted chip holder for u to insert the new, programmed eprom

hotpoint fit a blank one, and program it from their laptop, but mere mortals arent allowed acces to it

and , no, unfortunately the eprom in your board wont fit the new board, cos its smaller , and yes, u can reffer to it as an eeprom if u like

hope this helps

[dodders15]

Re: Hotpoint WF 840P – The dreaded F-03 Error

OK helo, that all makes more sense now. The bits are on order so lets hope for a result. Needless to say, cleaning the board did zip for the problem.

Thanks for the help, this was just what I needed to feel confident in paying out some more hard earned cash. This is a great site for the confused and bewildered. I will report back the good or the bad news next week after the refit. Cheers.

[dodders15]

Re: Hotpoint WF 840P – The dreaded F-03 Error

Now having great difficulty finding anywhere that can sell me a new module and programmed EEPROM for this machine quickly. Despite web claims of delivery within 7 days, now that I have ordered, Partmaster say out of stock on modules with no promise date in sight and EEPROMs at least 28 days!

I had the complete run around from the guys at Hotpoint, which in the end boiled down to a basic refusal to sell parts to me because I was not an authorised Hotpoint engineer.

Sadly, even the parts locator service on this UKW site have also not replied today with any kind of information.

Things are getting desperate guys….wife starting to move towards the plastic, flicking through appliance catalogues etc….. 😥 Does anyone know a quick and reliable source of these parts anywhere? You may just be able to save my life ❗

[Dales-Electronic]

Re: Hotpoint WF 840P – The dreaded F-03 Error

Try a company called EMW in Mansfield they specialise in repairing these boards but are usually happy to send you one up front on the understanding that you send your duff one to them. If you give them your full model number and serial number too they will help you out. Telephone number 0115 964 2118 or website emwelec.co.uk

[dodders15]

Re: Hotpoint WF 840P – The dreaded F-03 Error

Thank you so much for this information. This looks like a really useful service from the website, and makes wonderful sense for a cost effective repair, keeping perfectly serviceable assemblies off the scrap heap.

I am in the process of arranging a drop off/repair appointment for Monday morning. I will report back to this site how things went. 😀

[dodders15]

Re: Hotpoint WF 840P – The dreaded F-03 Error

Very pleased to report that the help and advice from this site has resulted in a successful and economical repair of my Error F-03 problem. The temperature sensor was fine, it was indeed the power/control module.

EMW were incredibly helpful. These guys certainly know their modules!

I took my problem part in to see them by prior arrangement as a personal caller. I was able to get it tested, had the suspected fault confirmed and was provided with a correctly programmed service exchange module with 12 months warranty, in my hand a few minutes later at a fraction of the cost of a new part. This is genius!

The machine is now humming, domestic bliss restored 😉

I am sure that not everyone reading this is either inclined or equipped to go breaking their back inside their washer, untangling and unplugging all the necessary coloured spagetti, but for those who are, there is light at the end of the tunnel. Providing you work carefully and safely with the power off, take your time and make lots of notes on where things go, then this is certainly not beyond those with practical mechanical aptitude, electrical understanding, and an inbuilt hatred of throwing away perfectly serviceable technology

❗ Do, whowever, be very wary of the metal heatsink projecting through the plastic case of this module. Onboard capacitors remain well charged for quite some minutes even after removing the power from the washer. Give it some time to dissipate before getting your hands anywhere near it!

Many thanks again for the help of all contributors to this topic. I just love this site!

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