On Apr 19, 8:41*pm, Andy Champ wrote:
Because I've got old radiators, the return to my boiler when the heating
is running is pretty high. *Which means that condensing boilers, which
like a return temperature below 55, wouldn't be running at peak. *In
fact most of the time probably won't be condensing at all!


You could try altering the way the radiators are fed. Rads usually
seem to be connected across the bottom with internal conection used to
spread the heat within the radiator. AIUI if you feed in at the top
and out at the bottom (diagonal opposite) you will get a lower return
temperature for the same heat output (but lower flow rate).


Robert