Thank you Mr Smithy for that clue spoke to Bolier/Heating engineer again. And funny he also mentioned that it might bee a corroded Diaphragm and if so would set me back £140 :^(
For other readers here are some more syptoms, In a bid to pinpoint any leaks in the system I turned off all my raditors. Afetr doing so the boiler switched itself on and after a while i thought this is not right, so opened up the valve of my smallest raditor and the heating system switched off.
This morning I touched said raditor and it was boiling hot! even thou the heating system hasnt been switched on for 2 weeks! 3 hours later it was stone cold...
will let you know what happens tommorrom and how long i will be eating beans on toast when i fingers crossed get the system fixed.
Cheers
Alex
Alex
July 2007