Creating combined feed & vent

[Rhaynes91]

Hi

I have blocked cold feed into the central heating. I've tried system cleaner and using mains pressure but I cant shift the blockage. Unfortunately I can't cut out the blocked piece of pipe either as it's below the tiled kitchen floor.

So the last option is can I combine the feed and vent? I've read online that some people are in favour and some against.
I've attached a picture of the pipes in the loft. The feed is the flat pipe and the vent it the one going out the roof.

Not sure why, but you'll see someone at somepoint has cut both pipes and rejoined them.
So my question is, on the feed pipe where the join is, can I cap the old pipe and then simply make a T connection to the vent pipe to connect them?
Can this be done simply using plastic pipe and push fit fittings?

Thanks for any help

 

[SJB060685]

Yes you can repipe it to a combined feed and vent but I would want it all in copper.
The problem is though these setups can prove problematic when filling and trying to get rid of air.

 

[Ric2013]

Check your boiler instructions (usually available online if you don't have the original) to make sure the boiler is suitable for this kind of installation. Some older boilers do not have the modern safety devices and are not suitable for sealed or combined feed/vent installation.