Heating with 2 down feeds issue

[karlpestell]

Hi All

Apologies if it's not the right terminology but our heating appears to be split in 2 halves. What I mean by this is I drained my entire heating system down today but after draining it down, we found 4 rads still full of water.

We then discovered another drain off valve which was still full. Speaking to a heating engineer friend, he suggested we have 2 down pipes from upstairs.

We refilled all the rads and they all filled fine with no blocks from what I can tell.

Problem is that the rads coming from the 2nd down pipe are not getting warm, or only one of the 4 is warming up a tiny amount.

Any ideas what it might be causing the issue.

 

[twgas]

Air. Turn off the hot ones and as the others heat up turn them off until you get the last one going, you can then turn them back on, let them get properly hot, before turning off.

 

[karlpestell]

Air. Turn off the hot ones and as the others heat up turn them off until you get the last one going, you can then turn them back on, let them get properly hot, before turning off.

Thanks Mick. I will give it a go.