Christian McArdle wrote:
Generally, boilers are more efficient working to hotter temperatures

Eh?

Boilers are fundamentally more efficient at lower temperatures. This isn't a
design issue, but stems from the laws of thermodynamics. This is in addition
to the extra efficiency from condensing.


True in theory, but some boilers work better at higher outputs due to
other factors. I.e. non modulating boilers may suffer short cycle times
at lower output temps..and the ignition process can waste fuel.

Roll on nuclear power and all electric boilers..

Cheap as chips they would be...to make anyway.