I moved house last year and was told of the benefits of a hot water system using a "direct" boiler, ie no hot or cold water tank, no wastage of gas to heat water you may not want to use. What was not made clear was the amount of water that has to be run off before you get any hot water.
I contacted the boiler manufacturer and was astonished to learn that the boiler is designed to run off seven litres of cold water before it becomes hot - enough to flush the toilet every time you want to wash your hands. This means vast quantities of good clean water being poured into the sewerage system.
The attraction to builders seems to be that they are cheaper to install. But I am surprised and dismayed that such a system is allowed at all because of the wastage. Could not the Government Environment Agency take some action?
MAURICE D JEFFERY