my ideal isar he35 has been fine for the last 6 weeks since fitting until this week, i noticed the pressure had dropped to 0.75 bar from the usual 1 bar (recomended when cold) i topped it back up to 1 bar and it held this until the central heating had been on again, when it had again dropped to 0.75 bar. This has continued all week it never drops below 0.75 and works o.k. i can see no apparent leaks and the pressure release valve has not discharged any water, the maximum pressure reached when running is 2 bar. The only mention in the handbook of 0.75 bar is the pressure at which the expansion tank is pre pressurised at. has anyone any ideas
thanks in advance