I agree on the price paid to heat the water - we are lucky enough to have Economy7 or whatever it's called these days, so I use the immersion overnight to heat the water for the morning shower, then use the gas to heat water during the day.
Re an earlier thread, is there an easy way to tell how big the service pipe is off the main? Do you just use the Mk 1 eyeball and say it's 22mm? If that is the case, what size service pipe (typically) are Victorian houses receiving?
Thankss...R