Can you connect a dishwasher to the hot water supply?

Oliver Shaw
#1. August 15th, 2009, at 11:58 AM.

Hi andy,

Personally I feel it may be better connected to the cold supply, as you say the hot water will bake proteins on and shorten the wash cycle so results will be compromised!

Our Tecnik (economy Bosch) says you can connect to a hot supply below 65 degrees, but do advise against it, also the economy 50 cycle would be rendered usless! And the pre rinse only cycle would be hot and bake foods on while waiting for a full load to collect.

The fill hose situation, the cold ones are a plastic type material, but the hot ones should be a form of rubber. Our old Bosch dishwasher said if connecting to the hot supply, you need to send away for a special rubber fill pipe before doing so, but that was a long time ago. Whether there is any difference today I would not know. I have hot and cold (red and blue) fill hoses on my washing machine and they appear to be identical except for the colour! The difference in material me be internally though. The hot one may have a slightly larger bore for improved flow rate. Although my washing machine is connected to a cold supply using a “Y” adaptor. But the dishwasher is connected to a cold supply aswell, and the results aren’t perfect, but I feel that may be the dishwasher being a cheap job opposed to anything else, we use a good quality detergent, Finish.

HTH,

Oliver.

Dave
#2. August 15th, 2009, at 5:42 PM.

Miele recommend using hot fill for their dishwashers and Hoover also recommended it for their (now discontinued) HD97 triple A rated model which was on sale in 2003 – 2007.

I have a Miele which uses hot fill (and has done since new) – the wash time for a 75 degree “sensor wash” is 1h35 mins when the water going in is at 65 degrees; if I happen to have drawn a lot of hot recently and the cylinder has not recovered the wash time increases to about 1h55 / 2h when the water is around 30 degrees going in.

Wash results using Ecover tablets and Ecover rinse aid are superb whatever the inlet temperature. I did try using vinegar instead of rinse aid, as recommended by Miele, for environmental reasons but I have to admit that the results for glasses were poorer.

The pre rinse (which I rarely use – and Miele recommend NOT using unless your pots are very dirty and to be left for a long time, again for Environmental reasons) is hot of course, but I have never had any problems with anything being baked on. Indeed using the hot pre rinse seems to shift things better than my old Bosch dishwasher ever did on a cold rinse, although that was 18 years ago and at that time I understand the Bosch machines were made by Hotpoint, who we know are not especially highly rated.

I would highly recommend hot fill for any dishwasher – it certainly saves vast amounts of money and time.

Oliver Shaw
#3. August 15th, 2009, at 6:37 PM.

I though Bosch made Hotpoint machines?

18 years ago Hotpoint made excellent machines, it is only recently mainly since the Merloni take over has the quality some what dropped, maybe now should be called “COLDBLUNT”!!!

Also tried Ecover and found it to not be half as good as Finish, your experience is interesting to find that it works! Tried their laundry powder and had to rewash the entire load using my normal biological Ariel and a long 60 wash. Things did not even smell clean, and my work clothes came out asdirty as when they went in.

So perhaps having a dishwasher connected to the hot supply is not such a bad thing provided the water is not too hot. Particulally if like you Dave you have a free hot water supply. We could do with free hot water, but cannot fit solar panels due to our house being a listed building.

All the best,

Oliver.

Anonymous
#5. August 16th, 2009, at 11:44 AM.

Andy,

I know that, many many years ago Bosch did make dishwashers for Hotpoint, it is a hell of a long time ago though. This hasn’t been the case for many years now, Merloni make everything for Merloni, not buying badged up machines like Hotpoint did.

Regarding Ecover, useful as a snooze button on a smoke alarm IMHO!!!

HTH,

Oliver.

Dave
#6. September 19th, 2009, at 10:57 PM.

Not been back to this page for ages and only just seen the comments re Ecover.

I’ve got to say that I use ecover washing powder, Fabric Softener, Dishwasher Tablets and Rinse aid and they are all actually very impressive.

The washing powder works far better than Persil or Fairy non bio ever did either in my old Hoover washer or in my new LG. I do have to use it sparingly though as it is very sudsy. The fabric softener is good, but I must admit that I am not a big fan of fabric softeners anyway, so I don’t have a lot to judge against except Waitrose’s own brand which I used to have before Ecover. I can’t tell any difference between that and Ecover.

For dishwashing I used to use Finish, but it Finished off all my glasses and some of my better crockery as it is so very abrasive. To be fair it does carry warnings that it may affect your dishes and glasses and many comparison web sites and reviews such as Which? also warn that most traditional dishwasher detergents can do this. The Ecover tablets work pretty well and my glassware is nice and shiny, rather than looking like it’s been sprayed with a thin coating of PVA glue. The only thing that the Ecover tablets don’t seem to deal with is baked on mincemeat when I make mince pies and they boil over onto the baking tray; but Finish never touched that either. A good old Brillo pad and a sink full of red hot water seems to be the only way to deal with that one.

Ecover Rinse Aid looks, smells and seems to behave like Finish, Co-op’s own brand and Waitrose’s own brand to me. In fact it was because they all seemed the same that when I read in the Miele book that vinegar does the same job but is cheaper and kinder to the environment that I thought I’d try it, but I have to admit that it didn’t seem to do such a good job. I’ve also had a free bottle of Miele’s rinse Aid, which seemed to work fine but it looked just like tap water! Heaven knows what was in it.

It’s interesting to see the comments about Hotpoint and Bosch’s relationship: in my old Bosch dishwasher instruction book I remember clearly that it stated that for service you had to ring Hotpoint, hence my assumption that it was Hotpoint doing the making. I also recall that I bought that dishwasher from the Co-Op and they had the identical machine in at a lower price with the Hotpoint badge on it and also their own brand which was also identical on the outside but inside had grey baskets not white. This was back in 1988 and that machine really was utter rubbish. It was the worst ever buy that I have made in terms of electrical appliances. In fairness it was a slimline model and I don’t think that helped as I have heard many people say since then that slimline models don’t tend to work as well as full size, but even allowing for that it was a bitter disappointment and I got shut after a very few years, going back to hand washing my pots for about a decade before getting a Hoover dishwasher in 2003, which proved to be very good at washing but very unreliable (what do you expect when it’s a Candy in disguise – it even had Candy labels on the circulating pump and some of the electrical components in it) and then the Miele that I have now in 2007.

The old Bosch-Point that I had also had provision for hot fill I recall. Of course back then I didn’t have solar water heating but as it was going in a space where a washing machine had been I did connect it to hot water tap that was already there. The instructions for doing so consisted of telling you to undo the water inlet hose from the back of the machine, use long nosed pliers to pull out the strainer, then remove a small rubber pressure reducing device, put the strainer back and connect up. I did all those things but the machine would not operate as the hot water pressure was too low (back then I also had lead hot water pipes which were all furred up and had a very tiny bore!), so I had to put the rubber part back and use cold anyway.

A colleague of mine at work has just moved into a new house and has room for a dishwasher now so he’s been looking at them. He has a 12 year old Bosch washing machine that is still hot fill and he was horrified when he found that Bosch don’t do hot fill dishwashers as such, but after referring him to this site he went and downloaded the instruction manuals for some Bosch dishwashers that he is considering and is now quite happy to find that they (apparently – I have not verified this myself) state that hot water fill is OK. He’s very brand-loyal to Bosch so he was keen to get one of theirs if he could possibly use hot water.

Oliver Shaw
#7. September 22nd, 2009, at 4:48 PM.

Hi Dave,

You can still connect a Bosch dishwasher to a hot water supply.

I have had no luck with Ecover at all, their laundry powder was rubbish from what I could tell, not even a tenth as good a Ariel bio powder or Persil bio powder.

We use Finish detergent, salt and rinse-aid and find they work a treat, like you say burn’t on food needs a helping hand, such as Fairy Power Spray, then everything comes out clean.

We had a Bosch slimline Dishwasher, funnily enough bought in 1988 (the year I was born), and it was excellent, it got everything clean, even with own brand crappy detergent. So maybe yours was a bad one!! It was far better than modern Bosch. I have a 15 year old Bosch washing machine and thats also excellent, shifts all stains and muck perfectly.

Oliver.

Expertcat
#8. October 3rd, 2009, at 8:26 PM.

Did you know that most manufactuers dont recommend the tablets.
As I have found out the consumers still put in salt and rinse agent and with the 5in1 tablets (which has them all in) and so the machine will generate excess foam which causes water friction inside the machine hence poor washing of dishes.

The tablet idea is consumer led by the manufactuers of the detergent.

Just think if the machine was made to take just tablets would the manufactuer of the appliance still put in rinse aid and salt regeneration units the answer would be no so in therory the appliances wouls become cheaper.

Oliver Shaw
#10. November 25th, 2009, at 12:58 PM.

Hi Andy and Dave,

On the strength of what I have read on here and Daves experience I have put the crappy Tecnik on Hot fill only. Well the first thing I can say is it is not such a crappy Tecnik after all! It now does a pre-wash in hot water instead of cold, so there are no more grease blockages forming, the dishes are coming out spotless and the machine (now 4 years old or so) smells fresh. It has a regular monthly cleaning with Finish dishwasher cleaner, but still smelt, now on Hot fill the food is broken down from the off so nothing can vegitate inside the machine.

As it is an economy version of a Bosch there is no intensive wash cycle, just a “Normal 65oC” and “Economy Wash 50oC”. and the “Pre Rinse only”. None of these use the heater in the pre wash, so it was cold, all the grease built up inside the machine and made it smell, and as the soiling was not being softened by a warm prewash, it used to get baked on by the hot main wash. Not any more, our hot water is about 40oC just the right temperature for a “biological prewash”, the grease and proteins are broken down before the main wash can begin by the Finish powder which is biological, so no more dirty pans or hand washing either.

The new programme sequence for a Normal wash is:

Prewash (40oc incoming water temp.)
Mainwash (65oC heated by machine)
Rinse 1 (40oC incoming water temp.)
Rinse 2 (40oc incoming water temp.)
Final Rinse (70oC heated by machine)
Drying.

The new Economy wash sequence is:

Prewash (40oC incoming water temp.)
Mainwash (50oC heated by machine)
Rinse 1 (40oC incoming water temp.)
Final Rinse (65oC heated by machine)
Drying.

The Prewash only cycle is now 40oC but we rarely use it as the dishwasher is on once or twice a day.

It is like having a new dishwasher, it actually does it job properly and in less time, it has gone from 2:30 to 2:10 for a normal wash. Haven’t tried the economy wash yet but was the same length a normal.

I was very wrong to be sceptical of this, the only problem was fitting a “Y” adaptor to the washing machines hot supply so they could both use hot water, but all works and no leaks. I have to say there are for me no negative points, only a hell of alot of positive ones, everything in every respect has improved dramatically!

The manual for the machine says you can use Hot water upto 60oC (ours is never above 55oC or so but in the main about 40oC)but recommend cold – don’t know why, the dishwasher was rubbish with cold water. It washes betterthan our previous machine now and equally as good as our old Bosch bought in 1988.

All the best,

Oliver.

Oliver Shaw
#12. November 26th, 2009, at 2:40 PM.

Hi Andy,

I too agree that everyone is being treat like a child. We can come up with no logical reason why it recommends cold, with cold it didn’t wash properly and blocked up the dishwasher. Perhaps that is the idea, so you have to buy replacement parts or buy a new machine due to grease blocking the heater, sump and drain pump? It now does wash properly using our hot (warm) supply, it has been very frustrating for four years having to hand wash because the dishwasher ( a labour saving device) couldn’t get things clean.

I put it on the hot supply Monday afternoon, it has done a load each day and everything has come out spotless and the machine is as clean as a whistle. I will never use a dishwasher on a cold supply again now I have experienced how much better they are on hot, if ever we have to buy another we shall make sure it will accept a hot supply.

The hot water comes from the combi-boiler about 15 yards away, and it still takes in a full fill of hot each time its on, the only draw back is I have to run of the cold before the machine is initally put on, but its a hell of alot easier than hand washing all the pans, and still saves water in the long run.

Another reason could be the usual environmental bo11ocks, every thing we do, what ever it is we get this environmental shyte rammed down our throats, we take no notice in this house, people need to make their own choices and understand why, not believe these idiots who came up with global warming.
EnvironMENTAL……….you’d have to be to believe what they tell you!! IMHO of course!

Oliver.

Mel
#13. December 5th, 2009, at 6:46 PM.

Years ago, we used to have a Hotpoint branded dishwasher that was manufactured by Bosch (according to Which?’s review of it). It was a really good machine – washed much better than my current Bosch dishwasher, although maybe in part down to the Sun dishwashing powder we used to use in it. I recall that you could buy a hot water kit for it – I don’t know if this was just a heat resistant hose or what, as I never bought one, but the cost was over 30 quid! According to the Which review, the machine didn’t wash as well with the hot kit fitted – this would have been because the machine had a dumb mechanical timer and feeding in hot water would have cut out the washing period while the water was heating up – resulting in a shortened & inadequate wash length.

Oliver Shaw
#14. December 14th, 2009, at 4:42 PM.

Hi Andy,

Just an update on the Tecnik as it has been on hot water for 3 weeks now……..

Things have improved beyond all recognition, in 3 weeks we have only had 3 dirty items, opposed to at least something every day when it was on cold water. The machine does not have a smell and nor has the old stale smell returned. Also we used to get red spots on the white plastic, not only have they all been removed but are not returning. The filters were spotless after a week, now they rarely need cleaning instead of the 2-3 times a week previously. There are no residues building up in the machine and all prevoius residue has been completely removed. The pots no longer smell of detergent, so it must be rinsing better as well.

The outlet hose was also full of the red stuff, don’t know if it has gone, but after Christmas I will disconnect it and have a look, I will post the result.

All the above proves against what Tecnik (Bosch) say “We recommend a cold water supply…” It is just perfect on a hot supply, so it appears Bosch do not know what they are talking about, it was so bad on a cold supply I felt like throwing it down the tip, but now its great.

All the best,

Oliver.

Ps. To you and everyone have a great Christmas and a Happy New Year!