Bottle Air Vent in New Heating System

[mmmbllrd]

Hi,

I apologise if this has been covered before somewhere in the forum, but I just can't seem to find the answer.

I'm installing the pipe work and rads for our new CH system and getting a Pro to fit a Condensing Combi and commission the system. There's no existing system in our house currently, just two coal fires. I think I've managed to establish everything I need to do, but I have one question about Bottle Air Vents, or Automatic Air Vents/Valves. I understand one should be installed at the highest point in a sealed system to release any air, but in our case the boiler will be installed in the bathroom upstairs and is affectively the highest point in the system. The boiler has a vent built-in already at the top - is this adequate, or does it serve a different purpose?

If I need a separate valve, what's the best place to install it, as the pipework for the radiators will be run straight down from the boiler and underneath the floor. I've read that it should be installed in a horizontal section of pipe at the highest point (including the radiators), but how can I do this without needing to fit an extra loop just for the vent, or is that exactly what I'm supposed to do? I hope that makes sense.

Thanks in advance for any advise you can give.

Matt

[davetheplumber]

As the boiler is the highest point in the system you will not require any auto/manual air vents anywhere else unless you have installed any pipework that may cause airlocking (eg. taken pipework up, over and down to a rad)