My Ariston Combi A boiler keeps losing pressure from Central heating loop?
Heating loop pressure drops to the red line twice a day. Cannot find any leaks from any of radiator and no leaks reported from house downstairs. Have bled system several times. Checked pressure relief valve and does not appear to be leaking. Pressure drop is faster when heating system is operating. Mains pressure is usually only 1.5 bar. Any ideas?
Alan ferguson, November 2013
