A nice man from British Gas serviced my combi-boiler the other day and told me I needed a pressure vessel fitting on the water supply to my house.
He explained that when I turn off the hot tap, the hot boiler would cause the water to expand and thus increase the pressure in the cold water supply. He explained that this happens because there is a one way valve at the water meter and so expansion back down the supply pipe is not possible.
Now that's all very well, but why is this suddenly necessary after all these years. His remarks (and accompanying quote) were not motivated by the need to solve a problem. Nor had he put a pressure gauge on my cold water supply to see if the increase in water volume produced a significant increase in pressure in the volume of water in the length of pipe my side of the meter.
Please could someone fill in the blanks?
He explained that when I turn off the hot tap, the hot boiler would cause the water to expand and thus increase the pressure in the cold water supply. He explained that this happens because there is a one way valve at the water meter and so expansion back down the supply pipe is not possible.
Now that's all very well, but why is this suddenly necessary after all these years. His remarks (and accompanying quote) were not motivated by the need to solve a problem. Nor had he put a pressure gauge on my cold water supply to see if the increase in water volume produced a significant increase in pressure in the volume of water in the length of pipe my side of the meter.
Please could someone fill in the blanks?
