The only fly in that ointment is that the water coming into a cool (room temperature) drum is greatly cooled by the cold metal so you are in a similar situation like where a KA dw spent time and energy heating water to throw against cold dishware. Increasing the incoming water temp much above 140 might harm the water valve. While I regret that my SQ fl does not have a heater, I find that I can get around that by running hot water to the sink, a gallon or so, allowing the empty machine to fill with 140-145F water from the tap and letting it tumble for 3-5 minutes before stopping it and letting it drain. I load it and restart it with hot water, again purged until it runs at 140F, and get a good hot (140F as measured with one of those infrared trigger thermometers) wash for white towels. Alternately, you could settle for lower wash temps with a point of use heater and use chlorine bleach for whitening and disinfecting.