6 months after purchase the machine starting making "load clacking noise", and after about 1 year would occasionally stop
with F04 error. Clacking noise does not necessarily occur every time we get the F04 failure...

We got the pump replaced by service guy (expensive) who said problem was that the pump is cheap and gets "flat spots" where it gets stuck. With new pump, problem went away initially, but started happening again - so 1 year later got the same problem...

I've already read previous answer to F04 about cleaning out the pump filter, but in my case, that does not seem to be the problem - there was not anything in the filter (unless I'm looking in the wrong place).

SO, question is whether "replace pump" is the right answer again (and if so, is there a more robust version?) or whether we need to look for something else.

matt, November 2007

Checked impeller several times and got minor bits out. As it's built in an pump was replaced 6 months ago didn't fancy having to dismantle. Got the FO4 on drain so concluded it must be pump. Got the mop ready and something to catch water. Put it on spin without the front access cover. The water flushed out the culprit which I was able to remove. A small stone. No more FO4.

Karen, June 2020

Mine has been playing up for years, The pump has not failed but seems not to start at times and is noisy. Powering off/on or draining and spinning the impeller eventually cures it.

I had a look (turning machine upside down isn't hard and the pump is readily accessible). When taking the clips off the rubber pipes around it I found 2p blocking one and thought I had cured it but no.

Someone suggested on the web that the motor had flat spots....

I've bought a new pump (£15) on ebay and replaced it (easy-peasey - two screws and pliers to detach pipes). The pump is now quiet and no failures. DON'T FORGET TO PULL POWER PLUG OUT BEFORE STARTING.

You may be able to save the £15. I think it is called an induction pump so no brushes. The impeller was inconsistently resistant to turning. It can be pulled out (lever the impeller blades gently). There is a rubber seal but it was full with water. I have dried that out, reassembled and the inconsistency has gone. BUT it may need a new rubber seal to stop water entering again.

David W, September 2019

I have managed to solve the F04 issue with my Bosch washing machine. With the back and top cover off I could feel that the large grey ribbed drain pipe coming from the pump was under pressure but the actual same type drain pipe leaving the unit was not feeling under pressure. I removed the pump pipe and blew down it ok (yuk!) and also slipped a knife up into the cone type shaped filter and felt no resistance. With the unit on a spin cycle and the drain pipes under varying pressures I gave the cone shaped filter a few squeezes and the growling pump began to sound normal. The cycle completed without another F04 showing. Fingers crossed.

John sigsworth, January 2012

This is too late to be of use to the original poster but might help others ....
A while ago I had an f04 error on Bosch Exxcel washing machine. Checking t'internet on the old tom tutor I found that the error is likey to be either a blockage in the filter, a blocked drainage pipe, the little blockage detector pipe getting block or the drainage pump not working properly.

I look in the filter - nothing and I could see the propellor in the pump turning ok. I took the lid and the front cover off and checked the grey drain pipes by unhooking the drainage pipes and the sticking a curtain wire down them and blowing down them aswell. The little blockage detector pipe is only about 2foot long and very thin and runs up from an opaque plastic tube connected to the sump (below the drum) to a plastic oval shaped part that houses a pressure detector - disconnected it at the top and blew into it- seemed ok. Then had a look at the pump at the back of the filter. I could see a bit of soot on the pump case. I dismantled the pump and the back of the magnet coil were the single strand wire connects the 2 coils was black so I suppose it was slowly failing.

I'm no washing machine engineer and not very technically minded but this wasn't difficult to fix.

First off - Look up your model on the Bosch customer services website and look for spare parts and you should find a parts diagram - you'll need to do this to get the part no to order from them - pump cost me just under £60 and also if like me you've never opened the machine before then its a good reference guide.

Tools needed - star screwdriver or drill (dont know the technical term but NOT a philips though you need one of them too) needed to open it up; pliers (long nose are better) for opening clips; Bucket, towel and a baking tray for catching water.

Top tip - When your struggling to get the retaining ring back onto the big rubber drum seal - cross your arms.

Never looked but you tube might have some videos. I think Bosch site had a very basic video.

Got dad skills, September 2009