British gas have contravened the BS standards on my installation. No water checks were carried out so I had no heating from October until April. They carried out 4 power flushes to rectify but still the system is blocked. They admit that they do not carry out the water tests to the 7593 and do not check the PH balance even though the new rules are mandatory. The operations Manager did not know what the New Part L regs are so how are they being followed. The customer now has to pay to put right the block caused from the magnetite sludge running through the system and causing the massive block. Do not use this company.