First post for me need advice
i work as maint plumber at a boarding school
have been told to remove basin for new worktop and replumb.
it is on the top floor of a 3 storey building hot and cold are fed from two twin set lowara booster pumps tank fed from loft tank.
service valves are old type gate valves that have seized and won't shut off
cold and hot to pumps are 1/1/2" steel galv.
found a lever valve at ceiling height which i shut off which cut off cold to this bathroom.
so decided to put new 22mm lever valves above old ones so cut out the pipework.
when i did this i found that water was pushing up through still although valve was off and no water came out of the other taps in this area.
so wondered whether i needed to drain down to bathroom below and turn off booster pumps to be safe did not want to airlock the system.
advice please
