after the installation of my heating system i constantly get air in the bathroom taps, mainly to shower and bath. The boiler is a vaillant ecotec system boiler, and on a sealed system with a hot water cylinder. The supply to the cylinder comes off a cold water tank and only supplies this. Not sure if i still need an open vent or is it fine without one? or do i just need a bigger supply tank as at times i have noticed it drains very quickly when taking a bath.

paula, August 2008

Sounds like you have two problems.
First your header tank feeding the hot water cylinder should not be running out under normal conditions. Get a bigger one or double up using a second one.
Second, the air which is entering the system (because the header tank runs empty) should be escaping naturally up the expansion pipe which should be tee'd off the HW cylinder top outlet (supply) pipe. Sounds like you don't have one, which is dangerous.
For 'open vent' read 'expansion pipe' and the answer to your question is YES.

Cledlyn, August 2008

add open vent as this will help prevent air locks, upgrade to bigger tank

andy n, August 2008