Originally Posted by lateral
We have cold water expansion valves on the bottom of our domestic cylinders on inlet & I have never seen one emit anything. "Yea old rules" had none for a closed system.
They just want stick all these "value enhancers" all over the place so they can charge more. Half the time my clients want em off. On for the inspector off for decent hot water. My plumber sayes "yeah whatever take it off yourself."
F$#king liability. (But we don't have ice.)
I must not understand NZ English
all that well. Pardon but I assume a expansion valve is a pressure relief valve. If you have a accumulator/expansion tank installed after the pump, the heated water backs up into the accumulator and the relief (expansion?) valve does not pop. Add a check valve on the inlet and it, that is the relief/expansion valve will pop.
I for one don't think a check valve is worth all that much, Though some manufacturers, mostly british, may require one due to the material of the tank.