I had a new Combi fitted today (in the to-be-moved-to house).

Fitters told me that I should run this at 74 degrees.

Which I thought far too high, as

1) it makes the radiators too hot to touch
2) basic thermodynamics suggest that a better temperature profile will
result from having the radiators at the lower temperate for longer period
than a higher temperature for a shorter period

I tried to explain this but was met with

"The recommended temperature is required for the condenser to have any
effect"

and the completely bogus "the temperature of the water in the radiators is
set by the TRVs not the boiler temp. I couldn't persuade the guy that he
was taking bollox, he played the "I'm the experience heating engineer card
and I know better than you" card. ****

Anyhow, at my current house it is 55 and works perfectly well

what do you guys/galls do

tim