with well water, and maybe cause mine is so deep, no matter what is always chilly....summer or winter....but as an experiment, I took 3 100foot garden hoses, left them somewhat coiled on the ground, ran the hoses from the outside faucet thru the hose, into the window, hooked up to the hot water line of the washer....free solar hot water....
common sense tells you can only do laundry during morning to later afternoon hours for the hottest water, and once the machine finishes, hot water is replenished for the next loads....this worked well for me with 3 FL machines...