Bosch Maxx 6 not draining

[Isla WS]

Heeeelllp!!!

I am usually handy with keeping our washing machines going but this one is giving me nightmares.

The serial number is wab28161gb/13

So, the washer would not drain. I removed the filter and found it blocked with a coin, hair bobbles and fluff. Removing the debris didn’t work so I replaced the pump.

The fault remained so delving deeper I discovered that the transistor that feeds the pump had blown. New board fitted from Bosch…still faulty.

I have checked the rubber sump with the ball in it…all clear. The drain hose & u bend…all clear. Supply the pump directly with 240v (via the loom from the board)…pumps out fine…so that tells me that the wiring loom and pump are okay but the new board isn’t supplying power to the pump. It’ll even do a wash cycle before permanently showing 1 minute remaining and the washing symbol.

Am loath to say the new board is faulty though…am I missing something? Are there any other components that influence the board to switch the pump on?

[andyjawa]

Had the same fault on a Hotpoint last month and I was beginning to think it was the pcb. I went for the pressure switch instead and that cured my problem. Your part number for a new pressure switch is Bosch part number 00627460 @ £18.67

[Isla WS]

Ah okay thank you. The original PCB had visibly blown a transistor tho, the hose to the pressure switch is clear and there are no fault codes showing.
There are 3 wires to the pressure switch, does anyone know if (and which) I could bridge on the multiplug to trick the PCB into thinking the pressure switch was working?
I would rather prove a part had failed before ordering a replacement. Am considering just replacing the machine otherwise.

[andyjawa]

Do not know the answer to that one there are no wiring diagrams available my end to check and even if there was one it would be vague. Strange and rare fault I grant you, can only suggest going for p/swt and at 18 quid, or maybe less, could be worth a shot considering the expense of the pcb just fitted other than that sorry no other ideas.

[Isla WS]

Okay no worries thank you Andy…if only Haynes Manuals catered for washing machines lol

[electrofix]

where did the pcb come from and is it the correct one ?

have you checked it since you installed it as i have never had a stalled pump blow a board so something must be wrong

Dave

[Isla WS]

Hiya Dave,
Bought it direct from Bosch & it’s identical, all the programs select correctly etc.,

[kaibart]

Most bosch washing machine boards need programming and there is instructions with new pcb normally, other thing I would suggest to check pressure switch is make sure machine is off pull the pressure switch hose off blow down the pressure switch pipe to check there is no blockages you should hear bubbling water, also leave pressure switch pipe off and select pump out programme and see if pump runs. Kai

[Isla WS]

Hiya Kai,
Have done that with the pressure pipe to no avail unfortunately.
The PCB did come with some photocopied instructions to program it but I cannot access the programming mode on the machine, nor make sense of which number I need to use off the sticker on the machine. All said though, the programs all come up correctly on the display so am assuming it’s programmed correctly.
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[tubafan]

I’d sort the programming part first before trying anything else as otherwise you might be chasing a fault that isn’t there.

[Author]

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