Balancing radiators.

[Spedley]

I've just added 3 radiators to my system, about 12000 BTU total using about 40m of copper pipe.

When balancing the existing radiators, firstly I found that they were all fully open but then I found that a mere quarter turn from closed heats them up adequately (don't have thermometer, just ordered one).

Is this usual or is there a problem because this doesn't sound right to me?

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Ideal HE Mexico 18 boilder (18KW,61500BTU)
Wilo Gold 50 pump in position 3
3 bed semi (built 1957)
17m of radiators existing, 5m added.
0.8KW / metre used for rough calcuations.
All inlets (most thermostats) fully open

 

[Whitespirit66]

If the rads are near the pump, and especially upstairs rads, then yes, a quater turn is often enough for a rad. Other rads further away from pump and/or downstairs may need a little more.

Many small systems run OK with everything fully open. Then you added more rads which tipped the balance into needing to balance the system.

 

[Spedley]

Great, thanks. That fits perfectly but just seems wrong, especially if you start with all the valves fully open by 3 turns or more!