If it were only sole traders buying these very expensive and unnessasary heaters manufacturers wouldn’t produce them as it would be a very small market and not cost effective, Grippatank, Varitech , pure freedom and all the other firms fitting them do it to make money , and yes they make lots selling them , I think in a few years time hot systems will be the norm , air conditioning in cars used to be an expensive option now it’s generaly standard figment in Evan base models hot systems will be the same , ionics openly say that the vast majority of systems they sell are hot and they supply some very large window cleaning company’s with systems all over the world , weather you like or hate ionics it cannot be denied that they are market leaders when it comes to system sales , it’s up to us as window cleaners weather we buy them or not but sales figures are a proven fact that more and more are going down that route