John Lewis give 2 year guarantee on white goods appliances

Can you connect a dishwasher to the hot water supply?

 Comments from another article have ventured into the subject of whether you can connect a dishwasher to the hot water instead of cold. This doesn’t appear to be a clear-cut yes or no answer and there is conflicting advice even from dishwasher manufacturers with some claiming it’s more economical, and others saying it’s better to run a dishwasher using cold water.

Most dishwashers in the UK are supplied with a cold fill hose and with instructions to connect it up to the cold water supply. Most people do connect it to a cold water supply and they work perfectly well.

Many dishwashers can be connected to a hot water supply though and if so it should say so in the instruction book. However, if you do connect a dishwasher to the hot supply you should use a hot fill hose, which is designed for use with hot water. I’m not able to emphatically say that connecting a cold water hose to a hot water supply is running any risk. All I know is that fill hoses have always come in red or blue, or with a red stripe or blue stripe and sold as either hot or cold hoses. If this is pure marketing spin I wouldn’t be too surprised but I’ve never really thought much about it until just now. It is reasonable to expect that the individual requirements for carrying hot and cold water are different enough to require specialised hoses.

What are the pros and cons of connecting a dishwasher to a hot water supply?


Presumably it saves electricity as dishwashers wash at high temperatures as well as using high temperatures for the last rinse to aid drying. However, I can’t help wondering why if using hot water is so much more efficient they aren’t all coming with recommendations to use hot water and advising cold can be used if preferred instead of the other way round.


If the water is over 60 degrees it can damage the filtration system built into dishwashers so don’t use hot water if this is the case. My understanding is that hot water should only be set to 60 degrees anyway, which is the optimum setting for a hot water supply in most homes. If it’s much hotter the water is not only dangerously hot but it’s so hot you can’t use it for anything much without adding a fair bit of cold water. This begs the question, what’s the point of heating water up to such a high temperature only to cool it down with cold before it can be used? An exception to this rule may be for people using solar powered hot water where they can heat to higher temperatures at no extra cost. However, the potentially dangerous temperature consideration is still relevant depending on the age and abilities of the people who may use it.

Hot water supplies may not have the same water pressure as cold especially if supplied through a hot water cylinder in the airing cupboard. Hot water hoses are more prone to kinking too to you would need to ensure the hose isn’t under any physical strain as when hot water runs through it, the hose can go soft and develop a kink.

Hot water can bake some food onto plates and make it more difficult to clean.

My dishwasher has a 50 degree wash cycle. If the water inlet temperature is already 60 degrees this programme may be compromised.

Related Links:

The comments discussing this issue on the other article I mentioned

If you want to check your dishwasher can use hot water but don’t have the instruction book you may be able to download one here – download instruction manual for washing machine or other white goods appliance


In these tough times, wasting money is not an option. Do some research first. Which? have a genuine no-strings trial offer. For only £1 you get the following benefits -

  • 1 month access to all the information & reviews on Which? Online
  • Access to Which? Local - a database of Which? members recommended tradesmen and reviews
  • A copy of the Which? magazine delivered to your door
  • Access to Which? Legal Services
  • Get your Which? offer


asset.f.logo.lg If you found anything useful please share with friends, and support my site by considering using ads which are all on topic. Follow me on - Whitegoodshelp's Facebook. My free help resource sites can only keep going with your support.


  1. avatar Oliver Shaw says:

    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.



  2. 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.

  3. avatar Oliver Shaw says:

    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,


  4. avatar Washerhelp says:

    Oliver, Hotpoint are owned by the same company that makes Indesit. Bosch are made by the company that makes Siemens ( Who owns who? Who really makes your washing machine? )

    Regarding Ecover detergent, they didn’t do too bad on Which? dishwasher detergent tests, “This Ecover tablet is the best dishwasher detergent we’ve tested which has ecological claims.”

    Which is the best dishwasher detergent?

  5. avatar Anonymous says:


    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!!!



  6. 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.

  7. avatar Oliver Shaw says:

    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.


  8. avatar Expertcat says:

    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.

  9. You make a good point Expertcat. I use 3 in 1 tablets with good results but we don’t use dishwasher salt or rinse aid.

  10. avatar Oliver Shaw says:

    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)

    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)

    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,


  11. Very interesting Oliver. I hate it when people say things like you can use hot water but we recommend cold. WHY? They treat people like children too much. If someone tells me you can use hot water – but we recommend cold, I want them to say, “we recommend cold because …” so I can make an informed decision.

  12. avatar Oliver Shaw says:

    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!


  13. 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.

  14. avatar Oliver Shaw says:

    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,


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

  15. Warm or hot water rinses away food debris better than cold. I don’t often rinse items before putting them into the dishwasher except for plates with curry sauce or any other food dye that will stain plastic items. I notice the stuff rinses off first time under the hot tap, as the temperature dissolves it at the same time as rinsing it away. I used to spend longer doing this under cold running water (which wastes time and water), but one day I discovered by chance that hot running water does the job instantly. If I have to rinse food from something, I use the hot tap every time.

    With the pre-rinse/pre-wash being performed in warm water, this gets rid of a lot more food debris than cold water, so there’s less food to be cleaned off during the main wash phase, hence the better results I’m guessing?

    One thing I can’t understand is why the water and detergent mix gets heated above 50C too quickly on the hotter washes, when it should be warm (not too hot) for the enzymes in the detergent to work properly? Above 50C, the enzymes in detergent get destroyed by the higher temperature. Maybe the warm incoming water dissolves the detergent quicker – especially tablet detergent, so it can be used for longer below 50C on hotter washes? Enzymes in detergents work best when the water is warm. I find my own dishwasher cleans fine at 45C and I don’t often use the hotter programmes. Some items will need soaking or spraying with something like Fairy Power Spray to loosen stuck on food. For hot washes above 50C, why don’t the dishwasher manufacturers consider keeping the main wash water at 45C for about 20 minutes, to allow the enzymes to work properly, before heating the water to the higher temperature – which destroys the enzymes?

    Regular readers of this website will know I strongly advocate using warm water in a washing machine to rinse off detergent better, as warm water both rinses and dissolves substances. Cold water is not very good at cleaning or rinsing anything.

  16. Absolutely, you can use hot water connection for your dishwasher. Many top brands like Miele, Asko or Bosh do not care if you connect their dishwasher to cold or hot water as long as hot water temperature is below 60 C.
    Using a warm/ hot water will reduce you electricity bill. All dishwashers have built in heating element and thermostat so they have to raise the temperature to 50, 60 or 75 C (depending on the chosen cycle). The dishwasher connected to hot water will use the minimal amount of electricity to heat water to the preset temperature. You do not need to be a rocket scientist to work out that heating a water from 50 C to 65 C is much faster than heating a water from let’s say 17 C to 65 C. Think about the hot water already stored in you hot water boiler, do not waste the money heating the water again but this time for the different purposes.
    Some manufacturers of low quality dishwashers will recommend the cold water only because if you use a cold water connection the washing cycle will be longer and due to this the washing results might be a marginally better. The same rule applies for the washing machines.
    The environmentally consciousness people will use the hot water connection for their appliances.

  17. Water connection mode is important for a dishwasher:

    * Cold water connection will use the least energy – the dishwasher heats its own water only for the parts of the cycle where hot water is needed, but the energy (in the form of electricity) generally costs more (unless you are on a time of use tariff, which is still unusual for households, and run the machine overnight).

    * If you have a gas or solar hot water system, models that can be connected to both hot and cold water will save carbon dioxide and operating costs, but models with dual connection are now rare. You will also save energy costs if you have an off peak electric hot water system.

    * A dishwasher connected only to hot water will use the most energy, although it may be more economical if you have off peak electric, solar or mains gas hot water.

  18. MIELE DISHWASHER MANUAL: “The dishwasher may be connected to a cold or hot water supply, max. 60 °C. We would only recommend connection to a hot water supply if it is economical. When connected to a hot water supply, all programme stages which would otherwise be carried out with cold water will be carried out with hot water, thus saving time and energy costs.”

  19. Thanks Graham: The Miele manual makes a sweeping and misleading statement, which can’t be true generally. It may be more economical for the dishwasher in that the dishwasher may well use less electricity heating up the water, but they do not take into account the cost of heating the water up elsewhere, which may come from a cheaper source such as solar powered but it may come from an electrically heated immersion heater which costs exactly the same to heat as the dishwasher would plus there’d be an amount of wasted hot water left in the pipework.

    The hot water might come from an inefficient old boiler cited two floors up with several metres of uninsulated copper pipework between them. In the latter case when the dishwasher had finished filling it would have drawn in several litres of hot water which would just sit in the pipework and go completely cold therefore wasting it. Also, the amount of water that the dishwasher draws into itself and the pipes may well be replaced in many people’s houses by cold water into the hot water cylinder therefore cooling down the rest of the water and triggering its heater to come on to raise the water back up to temperature.

    Therefore the actual costs of using that water vary considerably from house to house and are in most cases difficult or impossible to work out. The whole point of an appliance heating up its own water is that in many cases it’s cheaper because it only heats up the exact amount of water the appliance needs.


    If we imagine we want a cup of hot water to make a coffee, and we pour the exact amount of cold water required and the cup itself heats the water up. That’s got to be highly efficient. But what if we have a source of hot water already in the form of a big tea urn in the next room connected to a tap in the kitchen and connected to a constant cold water supply which replaces all water used?

    If we fill the cup from this tap it’s cheaper because the water’s already been heated? But the problem is that the first half a dozen cups of water that come out are cold or at best warm because it was several hours since we last had a coffee and all the water in the pipes between the tea urn and the tap in the kitchen has cooled down. So we draw off several cups of cold and warm water and throw them down the sink. That’s the first waste which needs accounting for.

    Then the hot water comes through ok and we fill our cup and have a nice hot coffee. The coffee cup didn’t need to heat any water so it’s more economical? For the cup yes! But after drawing all that water through we filled the pipework with boiling hot water again which is going to go cold quite quickly. Also, all the water we threw down the sink and the water that we used for the coffee is replaced in the tea urn by cold water from the plumbing, which in turn cools the water already heated in there and causes it to need to heat up a little more to bring it back up to temperature.

    Which is the most efficient method? Surely it’s letting the cup heat up only the exact amount of water required.

    That said, what if we had one of those new devices like the Tefal Quickup, which heats up only the water required for a coffee? In this case it’s cheaper (or maybe no different) to use this device to heat up one cup full. Or what if we had a tea urn in the same room heated by solar power? Then it would be cheaper to use that..

    What it boils down to is that it’s wrong to say one method is cheaper than another as it depends entirely on the source of the hot water and circumstances. In some cases using existing hot water will be cheaper, and in others it will be more expensive.

  20. It’s been a while since I’ve visited this page.

    Warm/hot water removes more food debris and results in better cleaning compared to having to rewash dirty items either by hand or using the dishwasher again? In the latter case, it costs more than just electricity, when you take into account the cost of detergent, salt and rinse aid.

    Warm or hot water removes food debris quickly. Next time you have strongly coloured sauce that will stain plastic items in the dishwasher, simply rinse the sauce away with hot water and you will see it comes off very quickly; try it with cold water and it takes much longer and uses more water. If your dishwasher is connected to the hot water supply, you could run the hot tap nearest the dishwasher for about 20 seconds until it feels warm; this does not waste water in the long run – it saves having to rewash dirty items. Also consider that during the winter months that the cold water from the street mains will be MUCH colder compared to hot water cooling down inside the copper pipes indoors.

    Finally, the longevity of the dishwasher should be considered. If cold incoming water is not melting the grease and food debris, the dishwasher is more likely to break down much sooner. On the strength of Oliver’s messages above, I wish I had a hot water pipe behind my dishwasher. Although I don’t have any problems with its cleaning performance, I make sure I use Finish dishwasher cleaner regularly and check the filters, spray arms etc. I have noticed white grease around the bottom of the door seal – I don’t like the thought of this grease build-up being elsewhere in the working parts! I’m assuming that the best results from using a hot/warm water fill would be achieved by using a programme with a pre-rinse before the main wash, along with a good quality detergent like Fairy Platinum?

  21. Most manufacturers offer nowadays warm fill options. The solar age is in full swing and there is plenty of free energy made available for the modern home.
    Here a BOSCH machine, max.temp.for water inlet 60 degrees Celsius:

    Click onto “Technical specs” on the data sheet, look there under “Technical Characteristics”

    As said, there are many more out there.

  22. avatar John Hadley says:

    Wow: what a lot of hot air about hot water! Interesting reading none the less!

    I have just had an Infinity instantaneous hot water heater fitted in my house on which I can set a water output temperature of 60 degrees. So, I thought why not plumb a hot line to the dishwasher, run off the standing cold water prior to each wash and wait for the electric bills to go down (we fill the dishwasher twice each day, and always set it on economy). However, your correspondence has inspired me to research alternatives: can I not use a cold detergant and use a cold wash: An American product called AJAX apparently will do just that. The secret ingrediant is BLEACH!
    All I need to do is to disable the heater and internal water temperature sensor in my Hotpoint machine and hey presto!
    Article below which focused on the issue of bacteria which your articles have not considered :
    In the study scientists washed dishes that had been covered with cheese, eggs, milk and jelly. They also smeared the plates with E. coli and other bacteria that cause food-borne illnesses. They washed one batch of dishes in hot, soapy water and found it killed off nearly all the germs. However, they got the same result when they washed the same bacteria-laden dishes using cool water and dish soap with bleach. Researchers also found that dishes washed in soapy room-temperature water, rinsed, and then weakly sanitized with ammonium-based chemicals achieved FDA-acceptable results.

  23. The EU comission has set up an organisation which gives consumer advise on energy usage in household and office, see

    They are suporting a web page where energy consumption data can be seen, containing some data about dishwashers as well, see


    None listed there which can not be connected to the hot water system.

    The very cheapest I came across recently – and which is not listed in the EU-topten list – is a counter model for 4 sets. It costs in Germany £98.- at a larger supermarket chain ( REAL market, Tisch-Geschirrspueler GSP 7 ). It takes hot water up to 60 degrees Celsius.

  24. As with hot-fill washing machines, the crux of the matter is thr price diffrence between gas-heated water and electricity-heated water. In the UK, it’s 4-5 times the price to heat water using electricity than it is using gas! Given that most of the dishwasher running costs are incurred from heating the water, it really should be a no-brainer for the manufacturers to design products around this – if necessary having a cold and a hot input and mixing it using a temperature sensor. Obviously people without any cost benefit could use cold fill only…

  25. avatar Anonymous says:

    Actually, it would NOT save on electricity. Believe it or not, cold water can more quickly be brought up to temperature than can hot water, because it is temperature DIFFERENTIAL that makes the difference.

    The same is true in reverse, of course: HOT water will freeze faster than cold water. Try it

Comment Policy:
Comments welcome, but need to be on topic or they won't be published. Please don't ask questions which are answered in the article itself or are only loosly based on the topic.

Speak Your Mind