I've just had a service and my 20 year old non condensing oil boiler is running very nicely at 91% net efficiency and 86% gross.
Does this mean the most I stand to gain from a condensing upgrade (in terms of fuel consumption costs) is the difference between 86% and the ~94% gross quoted by Grant and the like in their brochures? Or is the additional heat recovery from the condensing function additional to this?
Thanks
Does this mean the most I stand to gain from a condensing upgrade (in terms of fuel consumption costs) is the difference between 86% and the ~94% gross quoted by Grant and the like in their brochures? Or is the additional heat recovery from the condensing function additional to this?
Thanks