Have to look at my owner's manual, but IIRC two hoses must be connected (cold and "warm")water, regardless if one is going to use cold fills. My manual does state that one can use warm water fills to speed cycle times instead of heating cold water.
Remember these are timed fill (though will add water when it detects level drops)and like older mechanical dishwashers, the heating portion of the wash cycles is timed, rather than routed through a thermostat. Once the machine has reached the set temperature, you hear a loud "click" shutting off the the thermostat, but the timer will not advance until it is time. OTHO if the water is too cold and time has run out during the heating phase, the timer will advance, but the heating will continue until the proper temperature is reached.
To save on my electric, I almost always use warm fills,unless laundering really badly stained laundry. Even then will use a cold pre-wash then go over to "hot" wash cycle. When using machines of this vintage, you have to think like a 1980's housewife with the sort of products that were on the shelves then. By default the normal cottons, permanent press, and delicate cycle all have pre-washes. Miele changed this with the 1900 series to make pre-wash an optional cycle because modern detergents (Persil) and the great washing action removed the need for pre-washing. A wash starting from cold, or even cool or warm water and if need be going to hot will give great results these days.
This series of Miele washers has a thing about suds. They make all sorts of odd sounds if suds/air gets into the pump, so a word in your shell like ear; ditch any non "HE" detergents and stick with Persil. Gave away all my normal Tide products and only use Persil or other European detergents in my Miele and the results are spectacular. Clean and clear rinses (there are four of them, but only 1 half spin, 1 full spin between rinses, then a final spin), with great stain and soil removal.
One reason this series of Miele washers takes so long is that rinses are via dilution as mentioned above, and that before the final spin, there is a series of graduated spins for the normal "cottons" cycle. Mind you it does make sure that by the time final spin cycle starts, there is little chance of suds locking or too much water trying to enter the pump all at once, slowing down the cycle. Again, you will have much better results using Persil or a low/no suds detergent.
If you get the washer, I'm yours to pick for suggestions/tips.
L.
