Hi Neil
Have the same problem with an Ideal condenser boiler - engineers seem clueless but the last visit they fitted a new 'diverter valve' and the hot water was both 'hot' and 'instant' for a few days but then reverted to 'tepid' and 'intermittent':-/ If your boiler is the same as ours and switches between heating and hot water each time you turn on the hot water tap then sounds as if you have the same problem. Keep on at your boiler manufacturers if it is still under warranty - if not, we swear by the British Gas' annual service contract/Homecare 200 or even their one-off Boiler Rescue scheme. Good Luck.
ToniT, March 2010
