On 11/01/2019 23:33, Max Demian wrote:
On 11/01/2019 18:52, tim... wrote:
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"

The instruction manual for my Ideal says that the 'e' setting is best
for condensing, which is quite hot. I don't understand this as I would
have thought that the cooler the returning water temperature the more
condensing.

I use a much lower temperature as I don't have a room thermostat and the
TRVs are fiddly and don't seem to keep the air temperature constant.

If your boiler allows external timers consider getting a TADO or Drayton
Wiser (Or just wireless TRVs and a Reaspberry PI if you are the
adventurous type). Lets you see what temp the TRVs think the room is at.

Dave