One of the kitchen taps teeth have sheared and the tap is just spinning round - so I had the chance of a new set of taps from a friend.
Decided I would change them this weekend...
I turned off heating - shut off the cold water under sink and also turned off the stop cock underneath the hot water tank on Saturday - opened the tap in the bathroom (which is upstairs next to tank) to drain and also the taps downstairs - all drained ok but them I realised I only had 1 wrench!! So had to stop….
Sunday - I turned off heating - then slightly differently (not due to any reason) hot water first then the cold under sink - then opened the taps downstairs only - however it seemed to take ages for the hot water to drain and then the system started making some very weird groaning noises - different to Saturday….so I stopped opened both valves and all is working normally.
I am doing things right and the groaning noice is normal as the water leaves the pipes or was my system about to explode!!