<p>Not 100% sure about it, I thought these machines would anyway have the possibility to be connected to hot water, and built-in heater was used only to bring water to temp whenever supply didn't reach the " right" gradation of hotness, of course they could also be connected to cold only when hot faucet wasn't available, but time and energy use would have been much....it was of course preferable to have an hot faucet anyway, granted that your hot water source was not an electric one as well, but even there at least it saved the time... Not sure how it is/was in Australia though I think that electric water heaters didn't "last" as heating method as long as in the US (where today are commonly used) , or at least not as commonly, I mean the "switch" to gas or the seek to whatever cheaper started way more widely and before the US, better speak of earlier increment and or historically greater/considerable electricity costs vs others sources in Australia that made it happen....am I correct thinking this?
US have been blessed with chepaer electricity costs and alot of other factors compared to here.
In the US the centralized hot water in homes became common before than here also...
In europe, well with a few exception like France (Great nuclear energy production), or UK (coal) historically we didn't get many electric water heaters if not for the typical small wall hanged ones ( kitchen or bathroom, bathroom for the most) in locations or situations where you couldn't do otherwise, but since the early days they preferentially opted for alternative sources than electric so even for the early local ones ( before they were wood) so gas, and so of course happened later even for the centralized ones... but as said the commonness of centralized "hot water" came later than the US, many older buildings and apts still don't have it, but still the local ones....though newer buildings post 50s or anyway older and even ancient that gone through an internal remodelling does...OTOH europe developed a centralized gas availability that reach about * everywhere* so gas supply or limited space to fit a gas tank for the single homes is not that much of an issue like it is elswewhere, so for this and it's delivery and adjunctive costs... over here the nat gas reach pretty much everywhere....
Anyway....
Let's say that with twin tubs or wringer washers heating your own water was more economic than with an automatic, this in the days housekeepers did all the week washing in one day, at once, so consequent wash re-using the water, you heated water once and kept using it hot, till warm and ready for last loads of colored...
Infact they still lasted for long times in the UK...
Automatics, except for sud saver models (and keep in mind not everyone could have a tub to store it, actually very few given the laundry locations over here) , just throwed all the wash water away for every wash, and just used it once, then things evolved along with social and living style, people would not actually do all the laundry in one day, but when they needed in any time of the day, week etc.. So the twin tubs ( those who could switched to automatics before) as well as sud saving top loaders btw not common here , just quitted to exist at one point and everyone went forward with FL's....
Cold or cooler wash, we have seen it developping for many reasons, during the time, once it was just a claim of some detergents, though realist people realized what the truth was, this is happened in some places more than others, and I am sure that the reasons you mention also played a role in the Cold water detergents creation..sometimes you just couldn't get an hot wash...or enough hot water.....and detergents were the only thing one could rely in these situations....
Today....well....it's just warm instead of hot or cool instead of warm, is a trend...as it is in Europe and everywhere thanks to this enviroinmental craze, global warming theories, tree huggers etc... we discussed about it thousands times...
Claims everywhere about detergents working in cold water ( they all and I mean all, magically and suddenly started claiming being improved/changed to work as well in cold, persil, dash, ariel, sole, store brands...you name it', even though being actually the same as before IMO, all this thanks these Govs, US and EU bullshits agreements and derived trends to turn people to use cooler washes because this will save the planet! LOL), as well as bombardment of advices to turn down the temp knob from the actual TV, magazines etc...and we now arrived to the actual machines following this eco-trend to make money, claiming to work in cold as well as they does in HOT thanks to nothing else but " magical" powers LOL ...And in some places as we can unfortunately see this thing of temp is even indirectly "mandated" because of regulations and not even a choice, I mean with machines that will not fill complete hot water but mix it... OTOH life styles and mentalities changed furtherly generally for many people, and so did the laundry, now is not as dirt and stained as it was once, canons defining what a heavily soiled laundry or tough stain is, changed really much today vs what a very soiled or tough stain load was back then ... here is how some people (always more) is happy with these machines anyway...though not everyone..luckily...as we all know

[this post was last edited: 9/24/2014-10:05]