I would advise a Worcester Bosch combi, a magnaclean to protect heating circuit, a combimate to protect hot water circuit and a powerflush before its all fitted :wink:
If you press the pin in on the valve which is the same as a car wheel valve and water comes out then it needs replacing ,, if no water then repump to manufacturers spec !!
Agree !!!
I would speak to the owner on the quiet without the builder present and show him the proof that this could cause problems if left as is :wink: