Aaah, thanks for your help Margaret. Seems boiler OK according to maintenance man, Burner Pressure, ventilation flue, Combustion all came up to scratch (yes, am reading his report). He said is not that. Could be that the meter needs 're-calibrating' ? Must admt, have had notices for them to change it, but could never sort out a mutual appropriate time, and gave up in the end, so maybe me to blame ..
