I was of the view....cold cleans just as good as hot for many years unto last winter....I can honest say I have really missed out....first cleans its a dream, the cleaning power of HOT pure water is a very big plus, when we have the cold weather just knowing you have hot water in the van is a plus and having supple pole/reel hoses makes life so much easyer....for me its 100% no brainer...get a hot water system
this is the one I got and total love it 
http://www.windowcleaningequipment.co.uk/E-Z%20Heat%20System
I personally don't have a hot water system but do want one.
Some of the lads on here say it doesn't clean better
but that's like saying cleaning the dishes with cold water will be the same as hot? surely its far easier with hot water !!!!!
washing dishes and washing windows not a great comparison really is it.
on my 4 weekly maintenance cleans hot would make no difference
where you only have to do the bare minimum to clean...i imagine
really filthy first cleans,conservatories etc especially in the summer whendirt can be hard baked onit would be advantageous
but in the winter apart from supple hoses and warm hands i dont see
an advantage cold water freezes as quick as cold and f its hitting the
ground and freezing virtually on contact i gve up..salting wouldnt be
option before anyone mentions it lots of my customers have fancy drives
and would have a fit if i was dumping salt everywhere.
saying all that i am thinking about installing a immersion heater
into a tank in the spring as im really going to start pushing con
and fascia cleans in the new year and can see the advantages with
this type of cleaning.
if someone could make a easily transportable hot system hat plugs
into a custies outside tap..i would be grateful
