Dishwashers - do they heat water?

porsche959

Does a dishwasher heat the water itself or should I have immersion before starting it?

PirateShampoo

It will heat it's self.

vicwatson

Has built in heater

freddyuk

You cannot feed hot water into a dishwasher as it freaks out. It is designed to take cold water and charge you a fortune to heat the water from stone cold and run the cycle for what seems like hours. A couple of sinks full and the job is done in 10 minutes by hand (not me of course) and the hot water cost maybe a few cent with a solar hot water system - fact!.:D

ted1

freddyuk wrote: »

You cannot feed hot water into a dishwasher as it freaks out. It is designed to take cold water and charge you a fortune to heat the water from stone cold and run the cycle for what seems like hours. A couple of sinks full and the job is done in 10 minutes by hand (not me of course) and the hot water cost maybe a few cent with a solar hot water system - fact!.:D

Sime newer ones can take directly from hot feed as it increases the energy efficiency providing the water is heated efficiently.

SpaceTime

European dishwashers and washing machines all heat the water.

Some American dishwashers don't and very few American washing machines heat water.

Modern dishwashers use tiny volumes of water anyway so you're really talking about the equivalent of boiling a couple of kettles at most.

They take in so little water that connecting them to the hot supply is probably pointless as you'd need to run the water for a few seconds to get hot water anyway by which time the machine would be full.

They would have to boost the temperature anyway though as they usually wash a lot hotter than most hot taps. They also need to keep the water hot.

The other thing is European dishwasher detergent uses a cocktail of enzymes to dissolve food from the dishes. These work best at about 40C so the machine will usually go through a few different temperatures during the wash to optimise how the dishwasher tablet ingredients work.

There's more to it than you'd think.

You actually use less water and energy using a modern A rated dishwasher than washing dishes by hand!

The A+++ rated ones even use waste heat to and the room temperature to preheat water for the next wash or part of the cycle!

OldMrBrennan83

This post has been deleted.

heldel00

I handwash everything before I put them in DW. (What the hell is wrong with me? )

SpaceTime

Big energy losses in Irish houses are usually bad insulation and windows. You won't squeeze any more energy savings out of most modern appliances. They're the most efficient things in your house.

Look at heating, insulation and lighting. Your dishwasher's way down the list of energy hogs.

SpaceTime

Patww79 wrote: »

I'd say your run a dishwasher a fair few times, or even heat for the sink, before you'd afford a solar water heating system installation.

Unless you've a really bad dishwasher all you need to do odd roughly scrape them. Otherwise you're wasting a lot of your life and a lot of water and energy.

looksee

Just got a dishwasher for the first time ever, after years of hand washing - now all the kids have gone and there is just two of us, I get a dishwasher! I am a total convert, love it! It specifically says in the instructions, do not wash the plates before you start. I am very happy to obey

SpaceTime

Also avoid American sites about electrical appliances, plumbing and wiring. European stuff is often very different to North American ways of doing things. It can cause a lot of confusion.