Is using dishwasher more economical for me?

wazza2004

I have a normal boiler which you switch on to heat up the water. It is not a combi boiler. It comes on in the morning for roughly 10 minutes to warm the water up at least for washing the face etc. In the day kids will turn it on if they want a bath. Basically by the evening there is still some warm/hot water left in the hot water tank.

Currently when washing dishes we will boil water using a kettle and pour it into a bucket and add washing up liquid. We do the cups first etc etc. Then rinse the washed items under the hot water tap.

Have a dishwasher that I have not used in years. Basically thinking that it uses more energy. For some reason I thought it filled up the dishwasher with hot water which meant using more electric. Actually learned that it does not fill up the machine it actually sprays heated water onto the dishes.

Is dishwasher more economical to use in my case? My manual dishwasher (my teen-agers) moan about doing the dishes.

If dishwashers is better to use in my case any recommendation on how to clean the machine before use? It has not been used in years and it still looks ok inside and is mould free etc etc.

Thanks in advance for any replies

GrubbyGirl_2

If you have a smart meter why not take note of 1 weeks worth or how you wash up now and 1 weeks worth of using the dishwasher? In terms of water you'll use less using a dishwasher and you might find it's more economical than you realise.  Boiling a kettle takes a lot of power

Section62

wazza2004 said:

Is dishwasher more economical to use in my case? My manual dishwasher (my teen-agers) moan about doing the dishes.

If dishwashers is better to use in my case any recommendation on how to clean the machine before use? It has not been used in years and it still looks ok inside and is mould free etc etc.

If you find the instructions for the dishwasher it should give details of the amount of electricity and water used for each programme.  You could do a quick calculation to see how much it costs to boil the kettle compared to running one of the more economical dishwasher programmes.

One issue will be whether you have enough crockery, cutlery etc to be able to fill the dishwasher and run it once a day - the dishwasher will be more economical overall if you can fill it up before running it.  If you find you are having to run it after every meal then it won't necessarily be cheaper than the handwash method, although you'll get fewer complaints from the manual dishwashers.

Dishwashers usually have filters accessible inside at the bottom.  Check the instructions on how to access and clean these.  After you've done that I would run the dishwasher on a 'hot' programme (with nothing but dishwasher detergent inside) to give it a clean out. Other than that you don't need to do anything special to bring it back into use, although it would be worth keeping an eye out for leaks the first few times you use it just in case one of the rubber seals has perished.

Section62

GrubbyGirl_2 said:

If you have a smart meter why not take note of 1 weeks worth or how you wash up now and 1 weeks worth of using the dishwasher?

The difference is likely to be so small that a whole-house smart meter is unlikely to help identify it against all the other consumption variations.

A plug-in consumption meter would work, but as the manufacturer should have provided consumption figures it isn't really necessary.

macman

Assuming you only run the d/w when it's full or near to full, then it will use much less hot water than washing up the same volume by hand. However, the hot water in the dishwasher will be produced by electricity, rather than the gas-produced hot water from the boiler, so it will be about 3 times more expensive per litre.
Either way, it's fairly marginal, and there is little point in having paid out several hundred for a d/w and then never using it. 
It's a personal choice, but most people would be happy to pay a few pence more a week for the convenience of not having to wash up by hand.

Section62

macman said:

However, the hot water in the dishwasher will be produced by electricity, rather than the gas-produced hot water from the boiler, so it will be about 3 times more expensive per litre.

The OP says they boil the kettle for the washing up water, only using the residual stored (gas heated?) hot water for rinsing.

10 mins is not a lot of time for a gas boiler to recharge a hot water cylinder, so I wonder whether there are some other considerations/factor here?

gwynlas

You could go further in your calculations and factor in the cost of dishwasher tablets/pods versus liquid. We moved into a new build with dw and never used it except for storage however since using dw in current home would hate to be without one.I would think that a family including teenagers would find in invaluable in the scheme of things. Shopping around when pods on offer we now have sufficient for the coming year!

twopenny

I have a standard gas boiler runs the new immersion. I do it on gas for half an hour for toasty water all day, 2 or more in warm weather.
On electric it takes much longer. My old one was about 10 mins as possibly the thermostat had gone but as long as you remember to switch it off very useful.

So that depend s on what the op is doing. 

Do I take it a dishwasher runs from stored hot water or heats in in machine? Or does it depend on age or model?

macman

Your gas boiler doesn't heat the immersion. Your gas boiler heats the hot tank which presumably has an immersion heater in it as a back up? Re-reading, I suspect the OP's 'normal boiler' may be an immersion heater...
Domestic D/W's are all cold feed, the hot water is heated in the machine. They need a supply from the rising main/kitchen tap, not from a hot water tank, because the water needs to be potable.

wazza2004

Macman - You are correct. Boiler heats water by gas only. Dishwasher is cold fed.

The manual dishwasher might need to use the kettle twice depending on amount of dishes there is.

I will give the dishwasher a good wipe down, run it on quick rinse to check if any leaks then insert finish dishwasher tablet (still got a box of those) and dishwasher salt and run it at high temp to get rid of any gunge.

Thank you all for the replies