Bosch dishwasher performance deterioration - what to do?

dogfonos

Well-known Member
Would appreciate any advice/suggestions on this issue I'm having with a Bosch SMS461W00G dishwasher...

Started using my new Bosch dishwasher in early 2019. Not had a dishwasher before and was reasonably impressed with cleaning performance with my chosen cleaning program - until earlier this year when cleaning performance gradually began to drop off. I then started to use and extra half a cleaning tablet which helped for a few months - but in hindsight, just delayed the inevitable because now, cleaning performance most definitely isn't what it was, even with the extra half tablet. In particular, tea stained mugs are nearly always left with a few (usually faint) stain 'rings' whereas that just didn't happen in the first year of usage - and it's getting gradually worse. Some other items sometimes now also come out less-than-clean too. Results are patchy. Frustrating thing is, I've not been doing anything different compared to last year. And the machine is used only three times a week on average.

I use WHICH? recommended dishwasher cleaning tablets, ensure the salt and rinse aid settings on the machine are correctly adjusted for local water hardness and I've done all the usual things to try and resolve this problem:

  • Cleaned dishwasher (3 times in past year with propitiatory cleaner (once last week) and twice recently with distilled vinegar)
  • Filters cleaned every 3 or 4 washes but they are barely dirty because I don't load visibly dirty items into the machine (I get the pee taken out of me for that)
  • Always stack items thoughtfully
  • Even used a top-end Finish dishwasher tablet recently (recommended by Bosch) which actually gave slightly worse cleaning results than my usual tablets.
  • Dismantled the pump protection cover and examined pump, which was spotless (as was the entire machine - looks like showroom new)
  • I don't use an automatic program that senses level of dirt then adjusts water usage and/or time accordingly. Tried it once - no good because everything placed in dishwasher is pretty clean to begin with so machine doesn't sense dirt and decides little cleaning is required.
  • Some of the the tea stained mugs are new, some old so the problem isn't related to damaged surface finishes of crockery.
What's my next step?
 

RBZ5416

Distinguished Member
Are you using additional salt or just all-in-one tabs? I found additional salt necessary to remove tea stains in my hard water area, regardless of the tabs used. Don't know what tabs Which? recommend these days but never had good results with their recommendations in the past. But saying that I've found batches of Finish tabs variable as well. I currently use Fairy Platinum bought on a Home Bargains deal a while back,

So if you're not using salt try some & if you are, try cranking up to a higher water hardness level.
 

dogfonos

Well-known Member
Did your water supply or hardness levels change?

You prompted me to check today. Water hardness in my area has marginally reduced and dropped by one Clarke point (22 to 21). Still in the same Bosch band for water hardness (right at bottom of band, in fact), according to dishwasher instructions.

What I haven't checked recently is that the hardness setting has been retained by the dishwasher. If the dishwasher is anything like my malevolent Windows 10 PC, the settings may have changed themselves. Can't check settings at present but will this evening.

Are you using additional salt or just all-in-one tabs?

I don't really like all-in-one tabs. Prefer to keep things separate where possible. Dishwasher salt is added to the machine as and when.

I found additional salt necessary to remove tea stains in my hard water area,

That's a thought. Will up the salt usage for next wash.

Don't know what tabs Which? recommend these days

Nor do I. When machine was purchased, WHICH? recommended, among others, a cheap Lidl dishwasher tablet (W5 classic). This worked extremely effectively for about a year - not a tea stain in sight. It is possible that tablet formulations change over time so I tried a different tablet, Lidl's all-in-one, and reset the salt usage and rinse aid levels as recommended for that particular tablet. Result was the same - tea stained mugs.

I also tried a couple of Bosch recommended Finish all-in-one tablets (again, adjusting salt and rinse aid usage accordingly) but frankly, they're not as effective at tea stain removal as either of the considerably cheaper Lidl tablets. Apart from tea stains, all other items are usually well cleaned. Sometimes, starchy deposits aren't completely removed from saucepans but that's a compromise with tablets that are high in bleaching agents (and thus good at tea stain removal), like Lidl's W5 classic, which are probably lower in some other component (like enzymes) that remove starch.

you’ve topped up the rinse aid. You have haven’t you?

Yes, although rinse aid has more to do with drying efficiency, it seems.

There are other changes I could make such as using an intensive program but that would use more of the earth's resources and I didn't purchase an A+++ machine only to use the intensive wash option to clean items that barely look soiled - apart from the tea stained mugs.

Cleaning performance has declined over the 1.5 years of use. There must be a reason for this and I need to find it. My suspicions lie with either a change in tablet formulation (though the sketchy ingredients list is the same as it was) or the dishwasher spray jets aren't as powerful as they were (internal joint leakage or reduced pump power?).
 

John Simon

Well-known Member
We find that Fairy Original gel capsules are the best - after having one for 25 years.

Its worth checking that the arms are spinning and not blocked as ours were blocked with lemon pips :)
 

dogfonos

Well-known Member
Have you cleared the filters and spray arms and run a hot cycle with a cleaning solution
Its worth checking that the arms are spinning and not blocked

Yes. I cannot stress enough just how clean all parts of this machine are. Not so much as a grain of rice or lemon pip or similar sized pieces of solid debris have ever entered this machine. I rinse every item before placing in machine - always have done. In 1.5 years of use, apart from the odd bread or cereal crumb, I've never found any solid debris when cleaning the filters - and wouldn't have expected to.

The spray arms spin freely when nudged and are spotless, inside and out. I've removed both and examined with a torch. There are no solids or film coatings anywhere. In use, it sounds like the spray arms are spinning but, obviously, I can't see. Cleaning of every item, bar tea stained mugs, is still good so I guess both arms must be rotating.

I've recently carried out three machine maintenance cleaning cycles - the first using Finish dishwasher then two with vinegar. Cleaned twice before that with propitiatory dishwasher cleaners.

Interestingly, the machine required 2 vinegar wash cycles to remove a fine white powdery film on internal surfaces so maybe the film was chalk. I wouldn't expect chalk to build up if the correct amount of salt is being used for the purpose of water softening. Makes me wonder if the machine is not using salt for some reason - maybe the setting has been lost? Will check.
 

John Simon

Well-known Member
Yes. I cannot stress enough just how clean all parts of this machine are. Not so much as a grain of rice or lemon pip or similar sized pieces of solid debris have ever entered this machine. I rinse every item before placing in machine - always have done. In 1.5 years of use, apart from the odd bread or cereal crumb, I've never found any solid debris when cleaning the filters - and wouldn't have expected to.

The spray arms spin freely when nudged and are spotless, inside and out. I've removed both and examined with a torch. There are no solids or film coatings anywhere. In use, it sounds like the spray arms are spinning but, obviously, I can't see. Cleaning of every item, bar tea stained mugs, is still good so I guess both arms must be rotating.

I've recently carried out three machine maintenance cleaning cycles - the first using Finish dishwasher then two with vinegar. Cleaned twice before that with propitiatory dishwasher cleaners.

Interestingly, the machine required 2 vinegar wash cycles to remove a fine white powdery film on internal surfaces so maybe the film was chalk. I wouldn't expect chalk to build up if the correct amount of salt is being used for the purpose of water softening. Makes me wonder if the machine is not using salt for some reason - maybe the setting has been lost? Will check.
We had build up when we used Finish tablets, we got them from amazon so perhaps they’re fake or just not suited. Anyway those tablets are still in the garage 3 yrs later
 

dogfonos

Well-known Member
Makes me wonder if the machine is not using salt for some reason - maybe the setting has been lost? Will check.

The machine hadn't lost its settings. Shame, that would have been a quick fix. Anyway, I've upped the machine's salt usage/water hardness setting to maximum - that's two levels higher than previously (i.e. two levels higher than recommended). I'll try a couple of washes on these higher settings.

We had build up when we used Finish tablets

I think most tablets will eventually lead to a small build-up of chalk. Most cleaning agents are alkaline - even the dishwasher cleaners themselves, I suspect (must remember to check next time I use them) so there's nothing acidic to effectively dissolve/remove chalk deposits. The vinegar washes worked brilliantly. Dishwasher sparkles, racks slide easier on their runners and the top rack engages far more readily with the water connector on the back panel back.

Life is strange. Twenty years ago, if I'd thought I'd ever be agonising over a dishwasher's cleaning performance, I'd have ended it all! Tragic.
 

larkone

Distinguished Member
If you have only had it since early 2019 is it not still under warranty, most have at least 2 years
 

dogfonos

Well-known Member
If you have only had it since early 2019 is it not still under warranty, most have at least 2 years

They do but unfortunately the dishwasher isn't under warrenty. The dishwasher was purchased a year earlier but due to unforeseen building problems, it remained unused until early 2019. Sod's law.

Consumer law, though vague, seems to suggest an appliance should last a 'reasonable' length of time (whatever that may be), not necessarily covered by warranty. Guess 'reasonable' would be up to the courts to decide and I believe item cost comes into the equation.

Also, I can't be certain - or more pertinently, prove - the machine is faulty. Just because the performance drops off somewhat, does that necessarily make the appliance faulty? After all, the cleaning performance isn't that poor, most items are still cleaned adequately - it's just that it cleaned noticeably better for the first year of use. I would need an engineer's report to find the machine faulty in some way though I have little faith in anyone getting to the cause of this problem.

I will contact Bosch just to see if they can offer help but other than that, I'm becoming resigned to either tolerating the less-than-stellar cleaning performance or ditching the machine. I don't want to appear defeatist but there are just too many grey areas with this issue. I can't envisage a favourable outcome if I take the legal route.
 

psychopomp1

Member
OP,
why don't you try arguably the best cleaning pods, Fairy Platinum All In One? Believe me, all dishwashing detergent is NOT the same, I've found Fairy Platinum easily the best out there. Its not cheap if you pay full price, however Home Bargains sell this for a tenner for 70 pods which is a great deal. I think Asda do a trial pack of Fairy Platinum, something like 3 quid for 10 pods or so, so that might be your best option.

I also suggest running a hot water wash (at least 60c) from time to time to kill bacteria & built up gunk - if you're mostly doing washes at lower temps then there could be a build up of crap. I use this once a month to keep my Miele dishwasher clean.

 

larkone

Distinguished Member
Consumer rights say it should last 6 years so no reason not to contact Bosch. Personally I would suggest that maybe a thermostat has failed or is failing and it is not washing at the correct temp so cleaning performance is down.

My Miele was not cleaning tea stains properly, contacted Miele and the tech adjusted the water temp and the issue was solved. His opinion was that they set the temps to low to meet electrical efficiency targets not wash performance. He said he had had a few of these and they were all solved by increasing the wash temp slightly.
 

dogfonos

Well-known Member
His opinion was that they set the temps to low to meet electrical efficiency targets not wash performance.

Good point. I've heard of this. This Bosch is rated A+++ so I can see that is a possibility.

Personally I would suggest that maybe a thermostat has failed or is failing and it is not washing at the correct temp so cleaning performance is down.

I'll contact Bosch.

why don't you try arguably the best cleaning pods, Fairy Platinum All In One?

It may come to that - even though I'm more used to paying 5p/tablet and that worked fine for the first year. Not anymore though. Ideally, I'd like to discover the cause of the performance deterioration.
 

cottonpickers

Active Member
One other idea... Is it draining properly? Check hose at back is at correct height. Check exit pipes are clean/unblocked. Could be reverse syphoning.
 

psychopomp1

Member
even though I'm more used to paying 5p/tablet and that worked fine for the first year. Not anymore though. Ideally, I'd like to discover the cause of the performance deterioration.
When i bought my Miele dishwasher back in 2008 (first ever dishwasher i owned), like you I decided to buy the cheapest detergent as I wrongly assumed all detergent was more or less the same....so why waste money eh? However cheap detergent is cheap for a reason, so like with most things in life you get what you pay for. But like I said, Fairy Platinum can be bought on special deals from the likes of Home Bargains, Farmfoods etc. No need to pay silly moeny :)
 

RBZ5416

Distinguished Member
Just to add to my use, I started adding extra salt when using Finish All-in-one. That cured my tea stain ills but then I switched to Fairy Platinum on a Home bargains deal. Since posting previously I've realised that the extra salt has long since run out & I'm now running just the tabs on their own. Still no tea stains.
 
I have to add, we replaced our Bosch diswasher a couple of months ago and use the cheapest sainsburys own tabs and everything comes out amazing, much better than on the previous 10 year old model - also not using salt makes glasses cloudy in our area so and we werent using it at first. Really makes a difference using the salt. So I vote for trying the cheaper tabs, we find no difference from the platinums that came free with it and we drink a lot of tea and coffee. Might be because the dishwasher is new and better at it I dont know (also a reason I dont buy Miele as tech moves on and there worth if it your keeping for 20 years maybe)
 

dogfonos

Well-known Member
Is it draining properly? Check hose at back is at correct height. Check exit pipes are clean/unblocked. Could be reverse syphoning.

Things seem fine on that score. I did the installation of the dishwasher and undersink plumbing myself so I know it's done correctly.

I wrongly assumed all detergent was more or less the same....so why waste money eh? However cheap detergent is cheap for a reason, so like with most things in life you get what you pay for.

I chose the tablets I currently use based on WHICH? recommendations. The cheap price was a bonus. That was about a couple of years ago. I haven't checked more recent WHICH? reports and things may have changed. My point is: these cheap tablets cleaned better than the top-end Finish tablet samples recommended by Bosch and supplied with the machine.

Agree that not all cleaning detergents are the same but most contain the same basic constituents in different proportions. When we initially used the Finnish tablets, slight marks remained on tea-stained mugs so I looked for a tablet that contained a higher proportion of bleaching agent - such as Lidl's W5 original - and these did a great job. It also happened to be WHICH? recommended too. Not a smidgen of tea stain to be seen for the first year of use.

Because dishwasher tablet manufacturers don't specify the exact chemical composition of the tabs, I don't know if these Lidl tabs have changed formula slightly - it's a possibility. That's why I recently used the last of the Finnish tablets and the cleaning performance was found wanting - just as it was before.

I switched to Fairy Platinum on a Home bargains deal. Since posting previously I've realised that the extra salt has long since run out & I'm now running just the tabs on their own. Still no tea stains.

Several of you have recommended Fairy Platinum All-In-One so I will get some and keep fingers crossed, however, I'd still like to understand why my dishwasher's performance has deteriorated when I've done everything I can think of to keep it in tip-top order.

So I vote for trying the cheaper tabs, we find no difference from the platinums that came free with it and we drink a lot of tea and coffee.

That's my philosophy too. Try the cheap option first - especially if it's recommended by reputable testers/reviewers. I don't buy the notion that "you get what you pay for". It's just an advertising/marketing slogan which is sometimes true, sometimes not.

I ought to add that I always set the dishwasher salt and rinse aid settings to that recommended by the particular tablet used, taking into consideration my area's water hardness - yes, I'm that anal!

I'll Finnish (ouch) with a tip: Follow your main dishwasher clean with a distilled (white) vinegar hot wash - or even two consecutive vinegar washes as I did. There's a particular way of doing it so best Google it. Machine really sparkles. Reason is, most dishwasher cleaning agents are alkaline based so not good at removing the white film that often dulls the machines inside surfaces that you may not even have noticed. The film is probably sodium carbonate and is the result of the dishwasher's inbuilt ion exchange unit swapping calcium ions [=hard water] for sodium ions [=soft water]. All machines with a functioning ion exchange unit - and charged with salt - will have this issue. If you don't load salt, you're dishwasher will have a film of calcium carbonate which will also be removed by a vinegar wash (or two). Win win.
 

psychopomp1

Member
I'd still like to understand why my dishwasher's performance has deteriorated when I've done everything I can think of to keep it in tip-top order.
One very likely reason: as you appear to have a hard water supply, limescale has gradually caked up the internal cleaning components such as sprinkler arms etc over time and which you cannot see with the naked eye. Now of course using salt is supposed to prevent/minimise limescale but it could be that the machine didn't use the correct amount through a fault or for some other reason

If using a different detergent doesn't make any difference then I suggest raising this as a warranty claim with Bosch. They may decide to replace certain component(s) if they suspect they're faulty/knackered or as a last resort just give you a new machine, given that its fairly new.
 
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dogfonos

Well-known Member
OP,
Fairy are offering free 3 tablets of Fairy Platinum, can't hurt to try them!


Thanks for the tip off. I've just requested some.

limescale has gradually caked up the internal cleaning components such as sprinkler arms etc over time and which you cannot see with the naked eye.

I've been able to disassemble quite a bit of the machine's internal pipework and, using a torch and tiny mirror, can see most of the pipe's/rotating arm's internal surfaces. Before the vinegar washes, there was a very, very slight patchy film - difficult to convey degree, but it would most definitely not have affected water flow. However, they are now spotless, following the vinegar washes.

I await the arrival of the Fairy Platinum tablets with interest (Life has come to this!)
 

HMHB

Distinguished Member
Any more updates to this? I'm following progress as my dishwasher had a terminal breakdown a couple of months ago and I've still not replaced it yet. To be honest, washing by hand isn't proving to be a major problem at the moment!

My dishwasher that broke is a Bosch one and as it's 8 years old I was told that it might be as well to replace it rather than get it repaired. It had stopped heating the water and the air for drying.
 

dogfonos

Well-known Member
Any more updates to this?

'Fraid not. I still await the freebie Fairy Platinum tablets. I'm keeping an eye on Home Bargains store to see if they do an offer. At present, HB have an offer on Finnish tablets which haven't worked well for me.

My dishwasher that broke is a Bosch one and as it's 8 years old I was told that it might be as well to replace it rather than get it repaired. It had stopped heating the water and the air for drying.

Have you looked into the cost of a replacement heater or element? Many are priced at around £40 (though some are treble that!) so if you're happy with electrical DIY, it could save you hundreds. There are a few YouTube videos that show how it's done. Mind you, if you're unlucky it could be a controller problem. Or temperature detector...

Couple of months ago, my Bosch washing machine motor packed up. It's 19 years old! Probably done around 2000 - 2200 washes in total. Considered scrapping it but was reluctant because the machine is well made (as they were back then), has a nice motor, is clean, rust free and hasn't got any other problems so decided to investigate. Likely reason seemed to be that the electric motor's carbon brushes had worn out so I purchased a pair of new ones for £22. Fiddly but not too difficult to fit. Hardest bit was the physical manhandling (machine needed to be placed on it's side) without any assistance because of lockdown. Works great now though.
 

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