Feeding hot water into a dishwasher???

Greenman

My plumber is reliable not so dear and a 100% honest, but really is not so creative and always likes to take the easiest option. Our kitchen is circa 1950. Well we got a dishwasher and he went to fit it. There was a hot source connected to the cebtral heating close by so we checked the manual and it said water up to 60 degrees was OK. The water was feed in at 45 degrees temp, 2 different pals said feeding hot water in the DW was not ideal.
Has anyone any views???
Thanks in advance.

Victor

To a point it mean heating the water in one place and using it in another,w hereas using the dishwasher to heat the water keeps the hot water in one place. It all depends, is it cheaper to heat your water with electricity (in DW) or otherwise.

Note it is usually better to run dishwashers off peak (e.g. last thing at night) as they are heavy electrical users, expecially if you can avail of night rate electricity.

Greenman

Hi Victor,
Thanks for the reply. For me its cheaper heating water with oil, so thats good but can hot water been fed into the DW damage it?
Thanks for the tip on electricity I should look at a night meter. Installation costs over the saving!!!.

Victor

Originally posted by greenman
but can hot water been fed into the DW damage it?

I can't imagine this being so as most dish washers and washing machines actually have an option for a hot and/or cold water feed.

KoNiT

Greenman... are you sure the hot water sourced from the central heating?

That water is circulating through radiators & shouldn't be used for domestic use.

If you've ever removed a rad you'll see the rusty water coming out of it. You'll rust the lining of your dishwasher, not to mention possibly poisoning yourself!

Thats for indirect heating systems.

I'm not sure for direct heating systems, which your house could be (1950's). but I still think the water is seperate? I'd have to look at my old plumbing books

Greenman

Hi KoNiT,
Thanks alot for that. The System ( 7 years old ) warms the house ie radiators but also heats a seperate boiler thats gives us warm water, shower,bath etc!!!! So the old rusty water stays in the system!!!
Thanks alot!!!

joto

In the short term it might sound a good idea to connect DW to hot water feed, as DW uses approx 3KW electr. to heat water (3 units / hr.-expensive).

However appliances such as DW & WM's are designed to be fed from mains pressure water, even water from a header tank is not sufficient pressure to meet manufacturers recommendations. Thats why you'll always see a DW beside the kitchen sink (the only tap in house with mains water.)

Mains pressure makes them "self cleaning" as no sludge or contaminents will build up, eg. limescale. So in 2-3 years time you'll be looking for a new DW. DW's don't generally give trouble though as few moving parts.

Greenman

Hi Joto,
Thanks for your informed reply. In Belgium we only use mains water ie in general houses don't have storage tanks!! Mains water is fed directly into the hotwater tank. I have to say the pressure from the hotwater tank is very good it feeds our bathroom and I have to say the shower pressure is great!!!.
Not sure about the ROI but here because of the hardness of the water we put into the DW as directed by the instructions 1kg of special DW salt, the goodlady also puts powder and rincing liquid.
I would appreciate your opinions Joto on what I've said. I might drop into the shop I bought it from, they have a long history in the business!!!
Thanks alot

joto

Hi greenman,

Well I'm not a plumber but I work in the fitted kitchen trade. I've fitted a lot of DW's, but never to hot water supply. In Ireland we have to put salt in also. (btw u can get a tablet that does all "three in one":- salt, rinse-aid & detergent).

However I can't see a problem if it's a pressurised hot water system as you seem to have. It would be a definite saving on electric bill.
It's against water regulations in modern houses now to run hot water direct from mains. All new houses have a header tank. Less risk of contaminating mains water.

But in 1950's things were different! Less regulations-if any.

Greenman

Thanks Joto,
I'll leave it till we get the few bob together for the new kitchen that the wife would like, but thats for another day.

Victor

Oh, beware of the DW drawing water away from your shower!

Greenman

Both showers are Grohe thermostatic taps, really great!!! Was that your point?
Thanks Victor!!!

pipers

In Ireland, almost all dishwashers are fitted with a single mains cold supply.

However things may be different on the continent, Almost all appliances will have a theremostat within, so if you supply your DW with a hot supply it will only make up the difference in temperature (ie If its 45 degree in and 60 is required, the machine will only make up the 15 degree required).



I am a plumber and i see no problems.



www.pipersplumbing.com.

Greenman

Thank you pipers,
So far so good and heating with the oil is much cheaper. The wife is very happy with results of her new DW.
Things here are really different, electricity in a bathroom dosn't seem to be an issue ie sockets etc.Most people re use the rain water from the gutters for the garden and all new houses are obliged to have 5,000 litre concrete tank in the ground to save the rain water. I did mention that people don't seem to have storage tanks. Oh ye water is metered which I find and honest way of doing things.
Sorry for off topic!!!

fergald24

Pipers,

I wonder if you could give me an idea how the cost of getting a washing machine fitted and who would do this?

10-10-20

fergald24 - this is a thread from 2003! I don't know if Pipers is still on the forum.

Maybe somebody else can assist, but I would recommend that you start a new fresh thread!