Do modern European dishwashers have cold water input only, or both hot and cold water lines?

[passatdoc]

I'm aware that most FL washers (British Isles excepted) have used cold water input only for years, though now some TOL models offer hot and cold water inputs.

What about dishwashers? Do European dishwashers use both hot and cold water inputs, or do they have cold water lines only and heat the water with the onboard heater? (analogous to a FL washer).

In the US, as most people know, FL and TL washers have hot and cold inputs. Many BOL and MOL FL washers don't have a heater, and thus the hottest wash one can do equals your hot water line temperature. Upper end models with heaters usually engage when the "sanitary" (our version of boilwash) cycle is selected; on some models, if hot line temp is below "Auto Temp Hot", the heater may kick in to boost the temp to the Auto Temp setting (i.e. if two people are taking showers and hot line temp drops).

US dishwashers generally always have an onboard heater and will boost the hot water temp as needed to ensure constant wash and rinse temps.

 

[bertrum]

In a nutshell all European dishwashers and washing machines are now cold fill to comply with the Kyoto agreement.

The US refused to sign the Kyoto agreement so you guys can continue to have hot and cold fill and give two fingers up to the environment!.

 

[logixx]

In Germany...

Bosch/Siemens released a dishwasher that has both cold and hot water intakes. The three EcoStar models range from $1120 to $1900. They can be programmed to hot & cold or just cold fill - internal water heating cannot be switched off, though. I'm guessing they use the hot water fill for the wash cycles and cold water for the condensation drying cycle - as all other BSH dishwashers do. Consumption is 1.8 gal and 0.7 kWh on the ECO cycle with a hot water connection.

These models also have the water management system, which, as I just figured out by looking at the exploded view of one of these machines, stores water in a separate tank and reuses it. I'm guessing it might save the rinse water to use it for the pre-wash on the next cycle...

 

[revvinkevin]

I had NO IDEA that dishwashers could have, or do have BOTH hot AND cold fill connections! All of the US dishwashers I have ever seen (not that I've seen them all) only had one water supply line and that was connected to HOT.

I guess I need to research this KYOTO agreement because I don't see how filling a dishwasher with cold water and heating it internally (and running the pump at the same time?) could possibly save energy!

 

[appnut]

Here again the "problem" with U.S. is our standard outlets run 110 volt power and only two or three outlets in a house, at the most, have 220/240 volt power ratings. I've heard the explanation before, but don't remember all the techincal jargon. It would cost a fortune for all U.S. buildings to upgrade power brought in to the building, as well as having wiring placed throughout which could support the 220/240 type of power common in Europe. 110 volt just simply can't be easily done. Most people on here ocmplain about front loaders taking a long time here in the U.S. because water is heated so slowly. Having cold fills for both washer & dishwasher utilizing 110 volt power would take hours and hours to do one load. That's probably the biggest reason for the U.S. not endorsing this Kyoto agreement.

 

[DADoES]

 
My DD can (and typically does) run on a cold fill, and doesn't take significantly longer than the standard estimated time at 70°F to 80°F input. Last night when I checked, tap-temp (input to the water heater) was 54°F so that may take a little more time ... but not hours and hours.

 

[mrb627]

Agreed

Afterall, we are not talking about a large amount of water.

Malcolm

 

[appnut]

Yeah but, ...

The F&P is one of the most frugal of all machines per fill.

 

[DADoES]

 
Per a Normal Eco load run Fri night:

Input temp: ~65°F or less. Supply line not initially purged. Water heater set on 100°F, reported input of 50°F. Kitchen faucet ran 65°F at end of dry period.

Target temps: 125°F main wash, 125°F final rinse

Initial estimated time: 88 mins

Actual time: 101 mins (started 10:01 PM, ended 11:42 PM)

 

[brisnat81]

F&P had hot and cold fill dishwashers in AU up until about 2000. (not Dishdrawers) By default they filled with cold, and there was a button on the control panel, to select hot fill for the parts of the cycle that are heated. They werent popular as most houses only have a hot or cold connection, not both.

Bertrum, I dont see what Hot and cold fill has to do with Kyoto, Miele now push in their manuals to connect the dishwashers to a hot water source if you have an energy efficient hot water system, and you can add the hot fill valve on as an option for most Miele washers here at the time of order for the same reason, then you get cold fill for Prewash or Soak or Rinses and hot and cold fill for the main wash.

Michaels Mum has solar hot water, and we've just installed a new Bosch this weekend. I'd run it through here once before we took it up on cold, its connected up there to hot 50degC and its shaved about 15 mins off the cycle time. That keeps her happy and helps keep her electric bill down.

 

[favorit]

Kyoto what ???

Hi Bertrum,
that's not fair and moreover not true.
Heating water with electricity is not *technically* efficient.
Maybe it's *economically* in those places where electricity is cheap because of plenty of nuclear powerstations (France?)

I agree that the internal heater is mandatory to be sure of target temps (not a case we don't have washers without heater) but I do believe that a US dishwasher connected to solar made hot water or gas heated hot water is much more "green" than a cold fill only dishwasher.

Nathan/Brisnat wrote right : even my stoneage Miele G507 (1980) recommended cheap made hot water fill and since then my DWs are hooked to the gas hot water sys : no increase in gas bills but decreased electricity bills. Zanussi also has ever said it since those times (check Z80 Z100 manuals on serviceforce.co.uk )

@ Passatdoc : the double valve makes sense in washers (cold rinses) but is a nonsense in dishwashers. The single hot fill valve is necessary to purge the water line before the main wash and to keep the load hot till the last rinse. Dumbing down the load/machine temp with cold prewashes and prerinses would make useless the benefit of a hot water fill in the main wash and the last rinse

As Alex/Logixx wrote in BSH dishwasher the story is different as they have a condensor, somewhat alike those washer-disinfectors used for surgery items in hospitals

 

[l86810]

As far as I was aware the reason the hot fill tap was removed from washing machines in the UK and probably Europe was primarily for two reasons.

The first being that Enzymes have become much more an integral part of modern detergents and Enzymes de-activate above 40oC... rendering them completely useless in removing stains. Since they are such brilliant stain removers, it doesn't make any sense to 'kill them off' before they've even hit the drum.
By filling with cold water the machine can heat up to 37oC and hold it for 8-10 minutes before continuing to heat.

The second reason being that the huge drops in water consumption, mean that when the machine fills for the wash, the hot water barely reaches the machine (depending on where you water heater is), meaning most machines ended up heating from 30oC - 40oC anyway.

From what I believe Enzymes rally came into their own about the same time the huge drops in water consumption came about, and shortly after we had an increasing amount of cold fill only machines.

The whole hot water / no hot water valve, maybe based on washing habits and what your detergent is made up of in your country.

I don't believe its necessarily TOL washers that are beginning to offer hot and cold fill again, just 'ECO models' for people who do have an energy efficient hot water system located close to their machine.

However it does surprise me after reading through the thread that there are dishwashers which are hot fill only. As far as I knew the majority (if not all) of the dishwashers sold in the UK were cold fill only.
What happens if your incoming hot water supply is 65-70oC and you've selected a 'Delicate/Glasscare' prog.
And surly it comes back to the whole Enzyme thing as well, as they are used to breakdown fats/grease and other food deposits.

 

[dj-gabriele]

Both my dishwashers only have one water inlet and both are rated as cold OR hot fill.
So far I never seen a dishwasher with two inlets. Even on our new SMEG condenser drying machine. It circulates the inside air from the inside of the washing chamber to another outside chamber to condensate the moisture and doesn't use any cold water.

So, if you put the machine on cold water it will heat the water by itself, if you connect it to the hot water (at no more than 60°C) it will start with warm water and heat it to the desired temperature.

Now, I think that connecting the machine to hot water is not useful nor economical UNLESS you have solar hot water heating ONLY. Gas is not cheap enough to waste.

As an example: my (SMEG) machine does a 3,5 litres fill on average. The water, even if I have a recirculator pump, once in the dishwasher is cold. There isn't simply enough to purge the line even if opening the nearby tap, which is a waste. So we connected the dishwasher to cold makes more sense because otherwise, in winter we would need to heat those 9/12 litres of water per wash twice, first with gas and then with electricity, for nothing.
On the other hand, in Bologna, where my other dishwasher (INDESIT) is "wasteful", at 18 litres per wash, and we have hot water directly from the waterduct, once filled, the water in the machine was a little warm so there was an advantage, but, again, one litre of hot water costs like 10 of cold so I disconnected it from hot and put it on cold. The electric bill didn't change noticeably but the water bill dropped! (we use the dishwasher twice a day).