I think there is some confusion between "Dirt" which Hot - boiling or otherwise has no effect on and "Bird strike" which at the time of deposit was warm and soft - therefore any water nearing a temperature of a birds ar$e will soften the deposit and help it come off
Darran
This is something people fail to understand, hot water is beneficial on fats, grease, food etc, but has a much smaller effect on dirt.
dirt by nature (tiny bits of rock, grit) is cleaned best with agitation or pressure.
Hence the fact if you run cold water down a
window pane, then do the same with hot, the difference will be minimal.
It’s the brush and the combination of water that does the cleaning. Granted, hot does make a difference, but it’s minor for window cleaning.
Which is why I went back to cold, and haven’t ever felt the need to invest in a diesel heater. Saying that, I was interested in Rich’s, mainly as it was so small and compact, and ridiculously cheap .