I'm very confused as to what is happening with my hot water. For months now I've had this banging noise in the pipes, or what sounds like the pipes but nobody has been able to locate where it's coming from. It happens when my immersion heater, my boiler and washing machine are all switched off, so we just can't figure it out. In the last couple of weeks (since the boiler got serviced) I have also noticed that we seem on certain days to have boiling hot water, even though the boiler is switched off and the immersion heater is switched off and they have both been off for a day. I do have my washing machine on but I didn't think would affect the tap water? Also there is a pipe which runs from upstairs where the immersion heater is, down into my kitchen which always seems to be hot. I suspect (!!) this is where the hot water is coming from. Do you think my immersion heater might be broken? Why is the water hot when it is actually switched off? I am so confused and the plumber I had around said he couldn't work it out either! Any help would be very, very much appreciated!!!