Two days ago I installed 140 l indirect cylinder and 50 gallon loft tank, since installed I them I have a small amount of air coming out of the HW taps. The only differences from the old system are the increased size of the tanks, a surrey flange (ready for shower pump with valve closed) and the HW vent pipe which I have configured like picture below. Have I created the problem configuring the vent like this and should it go vertical from the HW.