On 03/11/2018 13:56, George wrote:

Also, on a different subject I have been living in a Mobile Home where I have my workshop and there is a gas heated water heater and I bought a water pump that comes on when I open any tap, this works fine except in the shower and as the pump starts and stops the hot water varies between boiling hot to freezing cold and I use a lot of gas and water dodging in and out of the water spray. Does anyone know the answer to this as the only thing that impoves the situation is by having the demand relay operating very quickly, which cannot be good for the relay contacts?

I had to use a pressurised accumulator tank. It solved the problem. It
was also necessary to make careful adjustments to the shower mixer tap
setting.

Bill