What setting for DU145 automatic bypass valve?

Have standard S plan, fully pumped, open vented system. Worcester Greenstar 18Ri boiler and Grundfos UPS 15-50 pump.

Am installing a DU145 (as currently has no bypass fitted) which has 6 settings and I believe required setting is derived from flow rates for pump and boiler but having trouble finding those speeds and not sure what calculation is required anyway.

Any advice appreciated?

The setting is more related to the flow resistance of the rads as its needed to open as TRVs close if you have them!

Generally the practical way is to start at the highest setting and turn on the heating when its all cold and then turn the ABV slowly down until the outlet pipe just starts getting warm. See the scale value and set it about 1/2 to one setting higher.

Usually about 0.2 or 0.3 if its scaled in Bar.

Tony

Thanks Agile - will try that.