Hi Mike & thank you
The main points that I was trying to make is that things have changed & moved on. In the "good old days" heat was everything & helped make inadequate products work better.
It is still the case with many old fashioned cleaning products now (regardless of industry).
Window cleaning used to be a nice hot bucket of something foamy & a scrub, nowadays most seem to have cold pure water systems.
My washing machine has no heater & is cold feed only but I don't use a traditional heat Dependant cleaning agent.
When I ran the Tm a by product of that was heat & an awful lot of it. At the time it was a necessity, however (& thank goodness) lots has changed & made this industry better. Yes there are still a lot of detergent cleaners on the market that all require some form of heat, albeit in the tank or as a pre-spray, however many suppliers are showing massive advances in detergent free products, phosphate free, non toxic, non carcinogenic, all of which USED to be a must in most cleaning agents in order that they may work.
Many people seem to forget that you are not "cleaning" with your extraction machine. Nowadays it is the cleaning solution that does most of the "cleaning" & that nice shiny, expensive machine that we have sitting outside is a "rinsing" tool.
Like a standard washing machine (hate that analogy but it seems to work) with its detergent in the ball it does all the cleaning with warm water, it then dumps it all so that it can complete a rinse cycle, which will be done with cold water (cost a bomb if they rinsed with hot water!)