On 12/01/2019 10:19, RJH wrote:
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.

Just found the manual for my Ideal Logic:

"The Logic + Combi is a high efficiency combination boiler which is most
efficient when operating in condensing mode.

The boiler will operate in this mode if the CH temperature control (C)
is set to the €˜e position (economy mode) or below. This control should
be set to a maximum for very cold periods".

I downloaded the manual and it omits the critical "or below".

--
Max Demian