This boiler design was bought by Potterton from Germany I'm led to believe and it's the worst thing the Germans have done to us since beating us on penalties! Whoever designed this had no thought for the engineers who would work on them or the poor consumer who got to know their service engineer very well. This is a terrible design,is always leaking and frequently failing.Condensing boilers will not last as long as a conventional non-condensing boiler. My favourite is the Ideal Classic fanned flue boiler. this is the most reliable boiler on the market and I anticipate it lasting us at least 30 years. When you think condensing boilers are meant to be good for the enviroment,they may give off less harmfull emisions but after 10-15 years you will have to replace it therefore you have a scrap boiler to dispose of and you have to use energy to make another!