Further to my topic 'Grundfoss pump circa 1978 bungalow' four topics back.
Short to the point Is it possible this pump has been tee'd in to the hot water flow to assist/speed up delivery to hot taps especially the kitchen which is 15mt away?. Just for record cold storage tank feeding the cylinder is above it in the loft. Drawing is assumed layout. the pipe on the drawing marked 5 is hot out flow goes down back of cylinder through floor under cylinder to front forming the hot pipe feed. The Grundfoss pump 4 is not level with top of the cylinder its half way down.
