"Christian McArdle" wrote in message
. net...
Before I fit it, is there any trick to calibrate these things
without the use of a pressure gauge?

Set it to around 0.3 bar. Mine had markings for this purpose. It will
start
opening even when not all the TRVs are closed, but this is a good thing
that
reduces noise through the radiators that are still open. The 0.3 bar left
over should be easily enough to push enough water through those rads.

Christian.



My system has three zones plus dhw.

Only one zone has TRVs.

Do I just need the automatic bypass valve in this zone?

Or should it cover whole system?



FrancisJK