yerrrr by far probly once every 12 months unless you bleed some radiators..have you noticed the presure relief pipe outside leaking water? fil the boiler to 1 bar..put on the heating and watch the presure gauge if it rises towards 3 bar wen in use the expansion vessels probly gone flat and then the water is released throught the presure valve to outside..wen the boiler cools down ure left with no water.. all it needs is to be re inflated with a foot pump..otherwise..youve got a leak on the sytem..same again fill the system t 1 bar..close the flow and return valve under boiler and leave over nite..if the presures ok then youve got a leak on the system..second option probly unlikely as you would have noticed if you had a leak that big!! hope it helps m8
toke, September 2009
