you haven't a clue and stop posting absolute cr-p , why would you not believe shambolic ( someone who works on boilers day in day out ) you are absolutely not able to take on advice , so stop advising and recommending a system you don't have personal experience with . like i said you need someone to talk so try the samaritans and stop recommending a fault ridden and unreliable system to new forum users . you say these heating engineers have no skills or knowledge when all you do is google your information from a bias gledhill or similar sites promoting their own products . get a life and stop promoting your utter rubbish with something you have no personal experience with . god forbid someone coming on this forum and listening to your drival and acting upon your information . if you love that system so much why have you not installed this system within your own property ????????????????????? . tradesmen in this occupation in this forum like to provide advise that is true from experiences and what EXPERIENCE do you have within this trade ?????????????? ( by the sound of it absolutely nothing ) . if your as clever as much as you think you are , THINK THINK THINK ??????? the money people might spend on heating systems from your advice or drival . you just don't take on board ADVICE due to your complete arrogance of intelligence and self importance , for once in your life think of somebody else for a change .