If the last post hasnt answered your question then this will, Crystal Clear who clean the Millenium Stadium, Welsh Assembley building use cold water, if they thought it would save a considerable amount of time they would use hot water. Remeber wfp has reached a stage where the market is very competative and now companies need selling points just like we do with our buisness ( uniforms, insurance ). Hot water is a selling point to make extra money, they want to make out that a diy system isnt good enough and this is the next big thing. You see this type of marketing everywhere ( windowwashers, you should know about computer companies and the way they make out a past system is dated and now you need this new one ) Luke