Complicated stuff plumbing is ...It will tell us that the system isn't wildly out and will only need the minimum of adjustments to get the column heating up properly. If it takes more then a more extensive balancing exercise will be needed.
If they all need to be off and there are only 7 rads then that column has a problem with either it's supply or the rad itself. A 2 year old combi on default settings should easily supply all those rads albeit with a bit of setting up.
Ill keep this post updates with my "balancing"