good point on DG ..I would think most modern>70s houses have it from construction, and for earlier houses (and Maggies right to buy) folks have seen sufficient property growth money to afford it; are further upgrades to triple glazing, bigger spacing/coated on the scale of diminishing returns, if government financed upgrades it would be a bottomless pitWhere is double glazing on that list. Its so bizarre the measures offered by the government dont do replacement windows.
Also the schemes I checked dont offer a replacement boiler, they just offer a boiler to those who dont have one.
I did my own maths, my gas usage would drop 60-70% with a new boiler. As the pilot light is the majority of my gas usage.
so have you measured pilot light consumption - with the ihd ?
my father gave me that gem from lewis, and looking up the install manuals and pilot light burner specs for their potterton boiler I could find nothing to substantiate it
was discussing with relation the 'saving' from changing a 20 year old non-condensing gas boiler(&storage tank) for a newer condensing boiler rated at 70% & 90% SAP efficiency,
SimonMartin Lewissays a pilot light vs electric ignition alone might cost £90gas/year , I'm sceptical on that told them to monitor it with IHD.
Equally the pre-heat on the 'modern' instant heat condensor we have is burning gas itself lol , although it is turned off during the day.
(It's the same deal with electric vehicles Kwh/mile is not the complete story.)