worcester 28i junior will not hold pressur after heating is off?

check the prv outside for a puddle of water. can only do this if weather remains dry.
suspect expansion vessel air pressure is low/empty should have 1 bar approx,= 15lbs psi . in without any water pressure applied in the system inflate using a car foot pump check/test with a tyre pressure gauge

wirecutterman
October 2011

Check if pressure relif valve is faulty

Ltd
October 2011