worester 28i greenstar

[wnjswozo]

bit baffled fitted boiler ,phone call to say boiler losing pressure,went back checked everywhere,where poss as 10mm pipe runs in drops,from loft to each rad,found small weep on hall rad valve fixed it,get phone call still dropping pressure but daily now,keeps topping it up.checked agian everywhere,checked prv ,dismantled prv pipework to see any signs of water,checked con trap by turning isolaters off on flow/return ,then re pressurized to see if con trap filled rapid,nothing.put ls1 one in as cant think of anything else.pipes buried in wall ,is a bungalow prop,any ideas