Troubleshooting a Miele dishwasher - no signs of life

Posted 27th Aug 2017Edited by:"morgie"
Hi all,

Hoping someone with experience of troubleshooting dishwashers, or an owner of an older Miele dishwasher may be able to help here - or point me to a useful online resource or forum more focused on this type of thing.

My particular machine in question is a G 646 SC Plus Dishwasher, it's from 2002 but the reputation for the German quality had been living up to its reputation until last week....and I'm hoping there may still be some life in the machine.

I'd noticed the machine had not been draining so well recently, but before I'd fully investigated and cleaned the impeller etc I came home to an electrical burning smell. Machine had tripped the power and blown the fuse in the extension bar it had been connected to. Fuse in the plug of the machine is fine. Connecting directly to power now and pressing the physical push switch to turn it on seems to do nothing - no power light, won't start when pushing the start button. The door switch is fine and definitely closed.

I don't believe there's a separate thermal fuse in this machine, but happy to stand corrected if anyone can tell me differently.

I've had the bottom off the machine, no signs of burnt wires etc. I have noticed the power noise filter and wondered if this could be at fault -…036 I've seen contradicting reports online, so saying replacing this in a "machine has no power" situation fixed it, others saying it won't stop the machine from starting up as is just there to stop interference with other appliances. I've tested for continuity across this and get nothing, I'd love to know if that's the sign of it being at fault or not. Has anyone ever tested one or can tell me what to expect here?

I'd also been given the suggestion of connecting power to the machine, turning it on (no signs of life of course) and with the bottom off pushing the float switch (as shown here) to see if that kicked the machine into life thinking it was flooded in the base, to start the pump. Tried this, nothing happened. If it had shown signs of life I guess it would have indicated that probably the machine's main control board was at fault.

Thanks if you've read this far. Hopefully it's made sense to someone - but ask me to clarify anything that's not clear. If I'm missing an obvious test on a apparently dead machine, let me know and if anyone can tell me more about the noise filter and whether it would stop operation to the machine that would be really useful.

Community Updates
Sounds buggered... might be worth calling a 'Miele' engineer?
Not a dishwasher expert but can understand the logic of what you've done so far.

You say that there is no continuity across the power noise filter - not sure how it should work in the powered down state. Have you tried bridging across it to take it out of the circuit then powering on?

Worth perserverring as likely a very simple fix.
Edited by: "Van1973" 27th Aug 2017
Thanks both.

To call out an official Miele engineer it's £125 for 1hr inc. VAT, obviously before parts. In my mind that's not worth it for the machine this age. I haven't enquired about any independent engineers, but been taking advantage of a lot of learning on YouTube.

I haven't tried bridging over the noise filter connections, might give that a go - thanks.
The noise filter is a capacitor bank so you won't be able to test it with a meter for continuity. For the 21 quid it might be worth changing the noise filter to start with. Anything else would probably be quite costly to replace
Our Bosch dishwasher started going straight into 'end' on the display lights, and nothing worked. We found out that the float switch had jammed. The resolution was too lay the machine on its side. Then stand out up and switch it on. I had to take the matrix of and clean it out to prevent this happening again. It's been fine for three years now.
Not suggesting this is what has happened with yours, but just to illustrate how a tiny thing can affect the machine's. Personally I would try to trace the power through from the socket first.
Thanks, I might take a punt on the filter and if not end up selling off other parts and buy a new machine....just seems frustrating not to know quite what the cause is.
Post a comment