Is this vented or unvented water cylinder?

Avalanche123

Hello,

moved into a house and I was under the impression that this is a vented system but in the old home manual it says it is unvented. It is vented, right? I am now doubting myself as I am not a plumber. Also, I want to find out which taps are under main for cold water, any idea how to do this? Will stopping the main feed work and putting the taps on? The ones which will not provide water will be fed by the main system? Thank you for any help!

Alter_ego

Does it have a small header tank in the loft?

Avalanche123

There is a tank above it, large one. I dont know about another tank

Alter_ego

Your picture is not very clear regarding pipework. a small header tank would confirm but I think it's vented.

Avalanche123

Do you mean two water tanks in the loft?
When I get home, I can take a different pictures of the pipework. 

neilmcl

If it's fed by a header tank rather than directly form the mains then it's a vented cylinder. Is the header tank in use or is it from a previous installation?

Avalanche123

There is a water tank in a loft. This the original instalation and I believe the water tank feeds the cylinder. The cold water pipe comes from the loft space. 
Asked my son to take some pictures

grumbler

Alter_ego said:

a small header tank would confirm but I think it's vented.

A small tank is for heating. For a vented cylinder it's just a vent pipe over a big tank.

And that's the pipe on the photo at the very top of the cylinder. After a tee it splits into two pipes. One of them goes up to the loft as a vent pipe.

nofoollikeold

1. That is a vented hot water cylinder.
2. The pipe coming out of the top is the hot water output.  The vertical part of the pipe above the cylinder will go into the loft and end up as an inverted "J" over the cold water storage cistern (big tank).  This is the vent.  
3. As the water is heated, it expands, and the expansion goes up into the vent pipe.  Under normal circumstances that is all it does and the pipe handles the expansion.  If the water overheats, the water pushes up, into the "J" and down into the cold water cistern.  

Avalanche123

Thank you very much! 
I thought this can't be an unvented one. They normally have an expansion tank, right?

Avalanche123

Any tips on how to find which taps are mains?