Dishwasher plumbing advice

PrincessLou

We've just moved into a new house and bought a dishwasher for the first time. We have a combi gas boiler and the instructions say it can be plumbed into a hot or cold water system. Which would be better and most efficient?

McKneff

I thought dishwashers were only cold water fill anyway

southcoastrgi

domestic dishwashers are cold fill only

PrincessLou

southcoastrgi wrote: »

domestic dishwashers are cold fill only

No, it definitely says in the Hotpoint Aquarius instructions that either can be used. I just wanted to know which would be most efficient.

McKneff

Well, it seems that there is a blip in their instuctions. Unless it relates to other countries.

Just plumb it into the cold water system.

southcoastrgi

PrincessLou wrote: »

No, it definitely says in the Hotpoint Aquarius instructions that either can be used. I just wanted to know which would be most efficient.

no this is wrong, domestic dishwashers need to be cold fill & heat the water to what you set it to on the wash settings, hot water going into the machine will disolve the salt far too quickly, plus if your incoming water temp is 45 degrees how can you do a eco wash at 30 degrees, industrial dishwashers are normally connected to both hot & cold because of the short wash times that they use, take no notice of what it says & connect it to the cold fill.

keystone

PrincessLou wrote: »

No, it definitely says in the Hotpoint Aquarius instructions that either can be used. I just wanted to know which would be most efficient.

The dishwasher is going to heat the water anyway. If you connect it to the hot pipe you have to draw through cold water which was previously hot and subsequently cooled in the pipe before any hot gets there. By the time its done that the washer has got enough and won't draw the hot water which has now filled the pipe just in time to get cold again. Later the scenario will repeat itself in the washing cycle.

So if you connect to the hot pipe you will be heating the water twice first by the boiler and secondly by the washer. Hot connection is not at all efficient from a fuel usage perspective.

Cheers

jbainbridge

I would just connect the cold ... dishwashers use very little water so by the time the combi gets going the machine will have taken its fill.

cyclonebri1

There was an issue early on with dishwashers, it was assumed that a hot feed was best, but evidently it was found that it "cooked" food on to the the plates initially, and required longer to complete the cycle.

Cold water feed.

GrowingUp

use the cold or the dishwasher will try and re-heat the water you have already paid to heat

rxbren

use only the cold this is the same for dishwashers and washing mahines.
as it will still need to heat the water from the hot water pipe as the water from your combi boiler isnt hot till it kicks in and heats the water so by the time the washer has drawn water from the hot pipe the combi boiler wouldnt have heated the water enough.