The worst service ever. The worst company and customer service. We called the engineer to come and to fix the problem, not to perform a routine inspection. They that the engineer called Ben did not find any problems to fix and the system met manufacturer‘s standard. We are not sure how he missed that the main boiler does not control tap water temperature. It is pretty clear, when one presses tap water button on the boiler, the “Non applicable” message appears straight away on the main panel. The suggestion that very hot water is a result of both immersion and main boilers working together and as a result heating the water twice perhaps could have has some credibility. But, say if the main boiler heated the water up to 60 C, and the immersion boiler also heated the water to 60 C, all in temperature would still be 60 C and not 120 C. To us it is pretty obvious now the issue is with thermostat. We paid £120 and asked the company to come back to fix the problem. They have refused and said only if we pay again the engineer will come. Its the worst experience I had in my life. Even 1star is TOO much for them. Read the reviews and don’t waste your money