Rate of heating in a living room?

[Mossop]

If a radiator has been correctly sized for a room and the boiler is adequate and fully functioning, at what rate of C/Hour would you want a living room to be able to heat up at?

Thanks.

 

[Mossop]

WBosch have informed me that the minimum central heating rated output for my boiler is 7.2 kW.

The other rads which I had on on the other level, are:

Double panel radiator: 42" x 23" (107 cm x 58 cm)
Single panel radiator: 47" x 28" (119 cm x 71 cm)
Acova column rad: (60 cm x 62 cm) 3540BTU 1037W according to manufacturer

I have now switched off all 3 rads above which are on the other level, and looked at the boiler where the cycling has returned.

Below the rads on the same level as the main rad in question are open again just slightly at their lockshields. So it's just the main rad in question which is on, the "other " vertical rad, and the other two 1980/90s panel rads. So back to the original setup. The boiler is set to 60 C for all below.

With the lockshield on the main rad in question open only slightly the boiler cycle times (in minutes) were as below:

0:00 On
0:02 Off
0:05 On
0:09 Off
0:09 On again
0:12 Off
0:15 On


With the lockshield on the main rad in question open fully the boiler cycle times (in minutes) were as below:

0:00 Off
0:02 On
0:04 Off
0:07 On
0:14 Off
0:17 On
0:18 Off
0:22 On

With the lockshield of the main rad in question open full, the flow has a temp of 59 C with a drop of 3.3 C. The "other" vertical rad has a flow of 61.4 C and a drop of 6.5 C. The other two 1980/90s panel rads have flows of 63 C and drops of 14 C. (The boiler sometimes ranged up to 65 C itself which explains some 60+ C temperatures here).

With the lockshield of the main rad in question open only slightly, the flow has a temp of 48.7C with a drop of 5 C. The "other" vertical rad has a flow of 61.9 C and a drop of 10.1 C. The other two 1980/90s panel rads have flows of 60 C and drops of 12 C.

 

[John.g]

Your total heating load is ~ just above the minimum output of the boiler so you will get continuous cycling when running on the 4 rads downstairs, you really can't do anything about this.
I would increase the boiler temp to 70C and note the cycling on/off times, this is with main vert rad valves full open, the other vert rad as is and remaining rads as is, if the boiler on time averages 3 mins then you will be doing well IMO.
Also see can you can range rate the boiler from the user menu, this means that you can reduce the boiler maximum (but not the minimum) output from its present 30 kw to say 10 kw or the next lowest setting, this won't affect the hot water output but should cause reduced cycling and more consistent radiator temperatures, if this option is not available then it should be possible to get it carried out at the next service. You can ask WB if this range rating is available on this model.