System boiler sizing?

[DP]

Cylinder spec often quotes figure like 70% delivery in 17 minutes etc which 2kw will never deliver especially when heating is also running.

You're assuming, then, that the CH is running flat out all the time? Is that usual where you are?

Here it is very rare.

couple of days ago temperature outside was minus, ice on van windows and at 9 am temperature was 1.5 degrees.
Is the cold enough for you?

 

[JohnD]

View media item 5710

 

[DP]

Good for you, why are you wearing a green jumber and long trousers, not sun lotion and soaking in the all that sun in your picture