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Have a Bosch WFF1201 washing machine that will not keep the power to the new heating element?
Last week the heater went bang and shorted to earth triggering the RCB and found out that the element had gone down to earth and was replaced and checked ok.
All functions of the washer run right down to the final spin and drain but the heater puts on 240 volts for around a second then stays of for the whole of the hot wash?
I have checked the thermistor in between the heater contacts which shows around 7K ohms with mains cold water and changes when slowly heated up with a hair dryer plus the lead to the timer board checked.
Have checked out the two triac’s on the PCB and the two main 36 volt relays which show clean contacts plus the diodes etc.
Have blown through the water level gauge pipe and gently pressurised the water gauge switch and the contacts seem to work. I am now running out of ideas and the cost of a new AKO 513 019 control board is over £150 for a nine year old machine which might not be the problem but the Bosch is in great shape.
Has anybody got any ideas with this fault as all I need is for the 240volts to stay connected to the heating element and not to switch off after the initial fill with cold tap water?
Chris
Re: Bosch WFF1201/GB/01 Washing Machine.
Almost certainly going to be the PCB at fault.
Sounds like the relay is dropping out due to load, probably as a result of damaged incurred when the heater went ‘bang’. Alternatively it could be chip damage, either way I’d put my money on a new PCB.
Not want you want to hear I know, but modern PCB’s don’t take ‘bangs’ very well 🙁
Re: Bosch WFF1201/GB/01 Washing Machine.
Moved to Trade 😉
I would agree with bagman also, most likely PCB, p/no 261037 £123.84 + the usual. 😀Greg
Re: Bosch WFF1201/GB/01 Washing Machine.
Thanks chaps.
Have been busy scratching my head about the problem; tend to agree with you all.
I can check most of the surface mounted transistors on the underneath and all the diodes on the board looking for a blown one without any luck. I did de-solder the main triac on the heat sink plus the small one standing alone and used a Peak atlas SCR tester which said they were working as triac’s. Both relays were powered up externally and the contacts measured less than 0.2 ohm so I had run out of ideas on this PCB. Main microprocessor I cannot test.
A few years ago I was brought round a company in Workington by a local service engineer which had some women repairing AKO control timer boards upstairs with a few test beds to run up these units and then sell as re-conditioned units to the trade but cannot remember the company name for a cheaper alternative.
Any more help chaps as I hate to be beaten on this one; I take it that the water pressure valve would not have taken the full belt of current when the heater shorted down to earth via the water in the drum. But the contacts did seem to buzz out when I carefully blew down a plastic pipe to change over the contact position.
Chris
Re: Bosch WFF1201/GB/01 Washing Machine.
FlyingBrick wrote:
A few years ago I was brought round a company in Workington by a local service engineer which had some women repairing AKO control timer boards upstairs with a few test beds to run up these units and then sell as re-conditioned units to the trade but cannot remember the company name for a cheaper alternative.Could that be ReLectronics 01604 639792 ?
I’ve not tried them myself but Phidom told me of them couple of years ago.
Mike.Re: Bosch WFF1201/GB/01 Washing Machine.
No, silly me. Workington is Quality Electronic Repairs.
http://www.qer.biz/
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