low water pressure- filling loop is reducing pressure(?)

[billposter]

Checked outside- water metre is indicating no leaks and spins when the tap is on- very low pressure, only sink tap works at half capacity. The boiler wont pressure up

EDIT: If i leave tap on and try to increase pressure on combi initially the tap water pressure increased but now there is no water at all. zero water pressure..

Any ideas? the combi boiler is an oldish Vaillant, was working fine last night. Could it be a mains leak in the street? wil go and check with neighbours now

 

[billposter]

east london mains leak affecting the whole area lol

sorry