Bosch dishwasher won't fill

[cjcoffin]

I have a Bosch SMS4452GB/14 dishwasher which despite its age still performs very well. But recently it has taken longer and longer to fill. Sometimes we need to nudge the programmer to get it to move. I have checked the incoming pressure and the filter in the inlet hose and both are OK.

Strangely once it has done the initial fill (on Programme 3 - mixed wash) it will then do the rinse cycles OK. Is there more than one fill valve, which might explain this?

We are in a soft water area so the softener has not been refilled with salt for a while, might this be a problem? Which part(s) of the cycle use water via the softener unit and which not?

All help gratefully received.

TIA, Chris

 

[ktuludays]

Before a dishwasher fills it will run the drain pump to ensure this functions correctly. Have you checked the pump isn't blocked? Is the pipe ok, drain ok? Does it empty into a fall pipe or under sink connector on sink trap?

 

[cjcoffin]

Thanks. The drain pump functions OK so I turned my attention to the inlet valve - which fortunately is accessible from the front after taking off the outer door and kick plate.

The 240V solenoid-operated part of it was working OK. The problem turned out to be the second, level control section. This too is a pilot-operated valve, and so has a series of small orifices around the diaphragm. These initially looked clear, but I cleaned them carefully with a pin anyway and reassembled the valve and the dishwasher now works fine. If it stays that way I will have saved £67 for a new valve from Bosch (or £85 on ebay!).

Now all I need to do is replace the appliance valve under the sink, which just when I needed it will not shut off tightly. Why are they such rubbish?