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And regardless of whether they are condensing or not, condensing type boilers have high surface area heat exchangers so they pull a lot more heat from flue gases than a standard efficiency boiler even at higher temps.
there are multiple technologies now to enhance the condensing effect that you get such as Weather compensation and priority HW systems on "System" boilers (ones heating a cylinder and radiators) where the boiler will allow a high flow temp to cylinder to reheat it quickly, but not heat radiators at same time, once cylinder is heated it then moves back to heating radiators at a lower temperature to get more time in condensing mode, weather compensation then allows even lower temperatures to feed to the radiators dependant on the outside temperature again keeping the flow temp lower when it can.
Combis can have additional heat recovery units built in now, where the cold mains water is passed though the flue gas to again get much more condensing out the boiler, before the cold water is run through the secondary heat exchanger to get the heat to the taps,
Its certainly not a scam, there are many regulations involved these days to increase the efficiency of units and controls as high as possible, where we fall down in this country is the regulation only says we must fit the equipment, it doesnt mean we use the correct size of heat emitters to benefit from it, we do training for engineers and homeowners very poorly so most benefits can be squashed very quickly by a few settings being left wrong on controls and basic set up.
there are multiple technologies now to enhance the condensing effect that you get such as Weather compensation and priority HW systems on "System" boilers (ones heating a cylinder and radiators) where the boiler will allow a high flow temp to cylinder to reheat it quickly, but not heat radiators at same time, once cylinder is heated it then moves back to heating radiators at a lower temperature to get more time in condensing mode, weather compensation then allows even lower temperatures to feed to the radiators dependant on the outside temperature again keeping the flow temp lower when it can.
Combis can have additional heat recovery units built in now, where the cold mains water is passed though the flue gas to again get much more condensing out the boiler, before the cold water is run through the secondary heat exchanger to get the heat to the taps,
Its certainly not a scam, there are many regulations involved these days to increase the efficiency of units and controls as high as possible, where we fall down in this country is the regulation only says we must fit the equipment, it doesnt mean we use the correct size of heat emitters to benefit from it, we do training for engineers and homeowners very poorly so most benefits can be squashed very quickly by a few settings being left wrong on controls and basic set up.