Hello all,
Underfloor setup is as follows:
Dedicated 22mm flow from 2 port valve
Dedicated 22mm Return which tees in to 28mm by cylinder.
11 Port Manifold
Grundfos 25-60 Alpha 2 pump on manifold.
Heatmiser setup but nothing is wired in as yet.
The problem is that when the pump is off, the...