Hi...We have these systems in our new build HA homes....we are in St Neots near Bedford...also another estate (same HA) has them installed....we are having huge problems and bills....we have now gone to houisng ombudsman to resolve as we are connected to gas so should not have has electric boilers put in.... We have a facebook page called NIBE BOILER PROBLEMS.. .the systems are only about 210% efficent if in the correct conditions but dont be confused with someone saying a gas boiler is only 90% effcient as gas is 3 to 4 time cheaper and produce 2.94 times LESS CO2 than electricity so is greener ...which means the NIBE would have to be a constant 300 to 350% effcient to even match gas.......its a huge con........