Avoiding Sludge

[conkerwoman]

Afternoon All

Thanks to advice on here, I have just had my Bosch SGS46E02GB/75 fixed. It stopped heating several years ago, when it was only 18 months old.

It needed a new heater unit and seal and it cost £170 in all to supply and fit the new parts, so much much cheaper than buying a new machine. And friendly, professional service too. Yay!

There were an awful lot of sludge deposits on the old parts, and the fixer-man said that it could have been the cause of the failure. I asked him how to avoid it sludging up again, and he said that using the hotter programmes would help. I was an avid user of the eco and quick wash settings I have to confess.

The water here is quite soft, but even so I have always used salt and rinse aid. Could these be contributing to the sludge situation? Also, I use Ecover dishwasher tablets. Could they be problematic?

And do the proprietary ‘once a month’ dishwasher cleaning solutions help?

Ta Muchly

Jakki

[Martin]

Re: Avoiding Sludge

Yes I remember replying to your earlier post on the subject and I’m pleased to hear that it is all sorted now. As for sludging up then there is little you can do to stop this from happening apart from rinsing off bowls and plates prior to loading. Gravy, soup, cooking oils etc left on crocks drain into the sump at the start of the cycle. There it is mixed with the incoming cold water and soon forms a scummy deposit on pipework leading from the inlet.

Whatever detergent you use will indeed flush away this sludge from all the ‘grey’ water (dirty water) areas but not so the clean water (inlet water) area. Hence the eventual inevitability of scummy build-up. The only complete resolve would involve switching from a cold fill to a hot fill supply and then there’s little chance of such a build-up forming. It is important to ensure the incoming hot water supply does NOT exceed 60 degs C and with a pressure minimum of 1 bar. I run my own Bosch dishwasher on a hot water supply and have done so on my previous Bosch combining a total of 25 years without any sludge build-up whatsoever. So that I regard as a proof enough consideration for you perhaps?

May your dishes always come out squeaky clean. 😀

[conkerwoman]

Re: Avoiding Sludge

Thanks again for your sterling advice, Martin.

My water pressure is quite low – 9 or 10 litres per min on the cold – dunno what that is in bars and pretty sure that himself isn’t going to be wanting to invest any more in this particular project. So switching to hot is probably not on the cards.

Pre-rinsing has always seemed like its missing the point of having a dishwasher to me, but I suppose I could give it a try if it’s definitely going to extend the life of the machine.

Is there no way we can manually desludge the inlet? Disconnect and flush through with hot water and detergent? I’m surprised that there isn’t some sort of filter system on there to deal with it.

My dishes and my hands are very happy this morning :tup:

[keepitsimple]

Re: Avoiding Sludge

conkerwoman wrote:
Pre-rinsing has always seemed like its missing the point of having a dishwasher to me, but I suppose I could give it a try if it’s definitely going to extend the life of the machine.

Is there no way we can manually desludge the inlet? Disconnect and flush through with hot water and detergent? I’m surprised that there isn’t some sort of filter system on there to deal with it.

:tup:

I had the same problem on a Siemens d/washer – solved thanks to help received on here. I think it’s a bad bad design from a manufacturer often recommended on here as making better than average machines. It isn’t too difficult to fix once you know how, but a nuisance having to pull the thing out, get the kickplate off and then pull out the short corrugated tube that connects across the bottom (its a push fit at each end with “O” rings, and once you’ve got at it it’s easy). Hot water and bottle brush did the job.

I’d now think several times before ever buying anything else from Bosch/Siemens/Neff, unless all the other makes have a similar design.

[iadom]

Re: Avoiding Sludge

All dishwashers clog up with gunge unless you take the trouble to rinse the dishes first and avoid using the economy washes all the time,it is not a design fault.

Using a dishwasher cleaner occasionally will also help.

Remember, it is a dishWASHER, it is not a waste disposal unit. 😉

[Martin]

Re: Avoiding Sludge

keepitsimple wrote:I’d now think several times before ever buying anything else from Bosch/Siemens/Neff, unless all the other makes have a similar design.

ALL manufacturers dishwashers suffer from this problem and ALL (without exception) advised rinsing crockery before loading in their respective User Instruction Booklets. Prevention always wins hands down over cure and applying this simply guideline eliminates the problem almost entirely.

I’ve seen customers tipping half full gravy boats, tomato soup bowls and plates loaded in leftover mashed potato straight into the dishwasher. And they expect a dishwasher that fills with ice cold water at the start of each cycle and slush all that lot will deal with that without it getting gunged up? Hey Ho! Ignorance is bliss I suppose?

[keepitsimple]

Re: Avoiding Sludge

Martin wrote:

keepitsimple wrote:
I’d now think several times before ever buying anything else from Bosch/Siemens/Neff, unless all the other makes have a similar design.

ALL manufacturers dishwashers suffer from this problem and ALL (without exception) advised rinsing crockery before loading in their respective User Instruction Booklets. Prevention always wins hands down over cure and applying this simply guideline eliminates the problem almost entirely.

You must be looking at a different instruction book from mine then. (Siemens SE26T251, page 11) States specifically “…Scrape off any large amounts of left over food ” (which I do, and that goes down the waste disposer) “It is not necessary to rinse the dishes under running water” So you can’t assume that all users are ignoring the manufacturer instructions. Also, although I confess to not doing it after every wash, the filters get thoroughly cleaned from time to time and don’t have much in them anyway, although I doubt this has anything to do with this problem anyway.

[keepitsimple]

Re: Avoiding Sludge

iadom wrote:All dishwashers clog up with gunge unless you take the trouble to rinse the dishes first and avoid using the economy washes all the time,it is not a design fault.

Using a dishwasher cleaner occasionally will also help.

Remember, it is a dishWASHER, it is not a waste disposal unit. 😉

See my post above about rinsing dishes not being necessary according to the manufacturer.

I’m not stupid. I do know that European dishwashers, unlike most of their American counterparts, aren’t waste disposers, and I have an efficient one of those installed in my sink.

Having looked inside the machine to fix this problem in the past, I can’t see how a dishwasher cleaner will do anything to resolve this other than make the manufacturers of it rich, as it won’t get anywhere near where this problem occurs. As far as low temp washes being the culprit, I generally use the auto 55-65 which according to the Siemens book is for moderate amounts of food residue, moderately adhesive.

[iadom]

Re: Avoiding Sludge

Ah well, Martin and my combined approx 90 years of experience counts for nowt, I bow to your superior knowledge. 8)

[keepitsimple]

Re: Avoiding Sludge

There’s no need to be sarky. Just pointing out that what you say all manufacturers recommend is not actually the case, so you shouldn’t blame user error as the source of the problem if they are following the book. I’ve no doubt that a lot of people DO get it wrong, but if someone follows to the letter what (e.g.) Siemens tell you to do, then if it fouls up there’s either something fundamentally wrong with the design, or, nobody told the technical writers they got the user instructions wrong. Of course any dishwasher manufacturer who up front told users “of course, because of the way we designed it you have to rinse the dirt off first” isn’t going to sell many machines.

[Martin]

Re: Avoiding Sludge

All that’s required is to apply a little common sense when loading a dishwasher, that’s all!

By the way, dishwashers in the US and Canada are very similar to European makes. More so now than ever before and have exactly the same user issues. Siemens/Bosch being an extremely popular choice over there too. 😀

[keepitsimple]

Re: Avoiding Sludge

They’re similar, but not the same for a variety of reasons. Last summer I went with a near neighbour (I have a holiday home in the US) who needed a new d/washer and asked me to go with her as she assumed as I’m English I’d know all about the “premier” European products :rolls: Mainly Bosch we looked at, and they were all hot fill which is normal in the US, so this sort of problem perhaps won’t happen with those versions.

She didn’t buy one as the ones we looked at worked out more expensive than a lot of the US made machines. Meanwhile, my old noisy and probably very energy inefficient Maytag trundles on. It was probably part of the kitchen fitment package when the house was new,10-12 years ago, and undoubtedly bottom of the range at the time. But – you can chuck anything in it and it grinds up the debris: doesn’t clog, washes fine, and fairly quick. Dries just about Ok if you leave it well alone for a while.

I dread to think how it gets treated when visitors stay there, but it’s never failed yet. If/when it does, I’ll replace it with the closest current model I can get to it, knowing that Maytag today probably aint the same quality as it was even a decade ago. 😐

[Martin]

Re: Avoiding Sludge

keepitsimple wrote:Mainly Bosch we looked at, and they were all hot fill which is normal in the US, so this sort of problem perhaps won’t happen with those versions.

In my experience there’s no “perhaps”, it just doesn’t. 😉

Also most in the US have waste disposal units located in the sink alongside the dishwasher so rinsing the crocks before loading is second nature to them!

[keepitsimple]

Re: Avoiding Sludge

If my hot water setup at home in the UK were a bit different I’d definitely run it on the hot supply – apart from anything else it would most surely be cheaper, and probably cycle quicker. Problem is a) there’s too long a dead leg before the dishwasher, and b) this house has a combi – this Siemens thing tends to take in water in small “sips” of only a few seconds at some points in the programme, so it would be constantly switching the boiler on and off, which I suspect will cause additional wear and tear.
From your own experience, do you know why Siemens say in the book that it’s acceptable to use a hot supply (up to 60c) but they recommend a cold supply ?

Starting to wonder whether the instruction book should be filed under “fiction” 😆

Edit – IIRC, during the drying stage the machine takes in some fresh water – presumably to condense the steam and assist the drying ? That probably wouldn’t work with hot water. That anything to do with it ?

[Martin]

Re: Avoiding Sludge

keepitsimple wrote:From your own experience, do you know why Siemens say in the book that it’s acceptable to use a hot supply (up to 60c) but they recommend a cold supply ?

Cold water entering at the lower temperature does allow for a longer cycle time which, for programmes of 50 degrees, can be more accurately temperature controlled electronically. Therefore eliminating any potential thermal shock problems. That at least is the theory, however in practice and with an incoming temperature BELOW 60deg C it’s never an issue.

keepitsimple wrote:Edit – IIRC, during the drying stage the machine takes in some fresh water – presumably to condense the steam and assist the drying ? That probably wouldn’t work with hot water. That anything to do with it ?

For those models that have an additional ‘heat exchanger’ and a cold water fill then drying is improved to some degree. However, and again from experience, I have never suffered any drying problems whatsoever on any cycle with the exception if ‘quick wash’. My quick wash programme takes exactly 35 minutes and, being a creature of habit I put it on at 10 pm most evenings. Once the news has finished on TV I turn it off and unlatch the door to allow steam to vent out. In the morning I empty the machine, the contents of which are completely dry. Sunday afternoons and its a full load that takes 1hr20m. Often as not, and because it is full to bursting I just switch it off and leave it. In the fervent hope my missus will empty it at some stage when she realises there’s no clean cups in the cupboard……..she never has to dry anything as she puts it away. 😉

[Author]

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