Just because you set your washing machine to hot does not guarantee that you are actually getting hot water into it. I found that it takes about 2 gallons of cold water coming thru my pipes leading from the water heater before it actually felt hot. I have a high-efficiency machine. 2 gallons is more than a load uses in the wash cycle, so hot water would never make it into the machine. What I did is put a high quality brass Y-splitter on the spigot. One hose to the machine, one hose looping around back to the drain. Before I start the machine I turn on the bypass hose until the water feels hot. This way I know hot water is ready to flow into my machine. I fill a watering can with the cold water to water plants, fill the fountain, etc.