What's the point of the hot water inlet on washine machines?

[st07]

Hi,

My mum lives in a flat with no gas supply, and is running on Economy 7. She uses an electric shower so the immersion heater is rarely switched on.

I've just been wondering what the point of the hot water inlet on the washing machine is. As far as I can tell, it draws in the right amount of cold and hot water, but with the immersion heater rarely being on, it'll draw in cold water when it should be expecting hot, and will use the inbuilt heating element to warm up the water, correct?

Surely the inbuilt element is more efficient than drawing hot water through pipes half way around the house?

The only time I can see a hot water inlet being the more efficient method would be when gas/combi supply is available - as gas units are far cheaper than electric. But still, at our house I'll have to turn the tap on for at least 30 seconds before hot water comes through, so surely a washing machine will suffer from the same issue?

Thanks in advance

 

[jj4091]

All your assumptions are correct, which is why most new machines are cold feed only. The only situation where hot & cold feed is a real benefit is where you have a hot water storage tank in close proximity.

 

[Inky Pete]

I think I remember reading somewhere that most washing machines only ever draw hot water for the very hot wash programs.

Since most people wash everything at 40 degrees these days, most hot water inlets will never get used.

 

[st07]

Thanks for the replies fellas

 

[Steve]

On a combi system, it would be better to feed both hot and cold inlets from the cold supply. Because, by the time the hot valve in the machine closes, all that the combi boiler has accomplished is to heat up all the pipes, a total waste of energy.

 

[handymanian]

Hot water valves we,re a selling thing.
Apart from false economy,most homes need the stronger pressure of cold mains supply.
A Y piece feeds both valves from the cold.