Identifying vent pipes

[Scott_1979]

Any easy ways to identity which vent pipe is which in the case? Both hw vent and heating expansion both go into the f & e. Don't often work with vented system much so any tips and tricks are appreiciated! Been dealing with loads of tasty blockages and air locks 🙁

The idea is to seal the heating first so obvious why I need to be certain.

 

[Chalked]

Check the cylinder too, it may be a primatic.! You can't have one on a sealed system.

 

[Chalked]

Must be another tank? The overflow tees off to the left.

 

[Scott_1979]

Yeah the cistern for the hw is to the left which makes me think the closest vent pipe is for the hw cylinder but was looking for ways to makes sure !

 

[snowhead]

That's an interesting setup with the overflow higher than the ball valve..
And looks like it's been covering the ball valve quite often.
Hence the rusty support plate.

 

[Last Plumber]

Are you saying that there are two tanks the same size next to each other ?
Are they married together ?
Is the cylinder primatic ?

It is a possibility, (unusual but seen it), that the hot water pipe has a high point and some previous plumber has put another vent pipe over the tank. If the cylinder is primatic, that could be the case. i.e. It might not be a vent off the heating and one off the hot water. It could be two vents off the hot water system. Not a recognised way off doing things but I have seen it done !

 

[Scott_1979]

Pretty sure it's just a standard hw cylinder I'll attach a few pics. It was only installed 2 years ago (the cylinder) after a flood.

And no they are separate tanks, when the heating was drained the hw cistern was still full