Brief background; visiting a friend with very old central heating - reminds me of what was in our last house when we moved in in 1984.
An old Glow-worm 85 100 floor standing lump of iron. Kettles like a really kettly kettle. Radiators of various vintages, some with suspiciously cool bottoms.
It hasn't been serviced recently (then again, these are so simple that there isn't much to service compared to modern boilers). This also suggests it might do with a flush and some inhibitor.
I suspect a power flush might improve the effectiveness of the radiators.
This is a large long and thin 4 bedroom bungalow with a lot of glass, patio doors, plastic roof conservatory as part of the dining room. So probably not that thermally efficient.
I am assuming that a new central heating system will cost more than £4,500; possibly quite a bit more given the length of the pipe runs.
Just wondering how long it normally takes to recoup the cost of a new highly efficient system through fuel savings.
For example, a £4,500 system would need to save £450 a year to pay back over 10 years.
I expect the costs to be higher and the savings per year to be perhaps a little less.
When you get past 60 long term investment looks less attractive, especially with a pay back tome of 15-20 years.
Piece of string question but just pondering.
Cheers
Dave R