One pipe system woes

[Johnny8718]

I was always taught that when joining into a one pipe system, no matter where, tees should be rad distance apart. For instance, if you have one pipe system running through loft space and you hang a 600 rad in room below, tees should be min 600 apart.
Injector tees would help.

Thanks for that. This is how the rads are tee'd downstairs. However where I have tee'd in, in the loft - I am using a flow and return from the boiler. If that makes sense?

 

[roguetrader]

So your using either end of a one pipe system. Your new rad is the first on the flow and the last on the return?

 

[doitall]

I was always taught that when joining into a one pipe system, no matter where, tees should be rad distance apart. For instance, if you have one pipe system running through loft space and you hang a 600 rad in room below, tees should be min 600 apart.
Injector tees would help.

Agreed RT but I don't think the new rad is a one pipe system, whereas the problem is most likely to be air in one or the other pipes where they drop from the loft.

Seems to me he has used the old gravity flow and return pipes, to feed back to the existing boiler which then feeds the heating, In short the old boiler is now in line. You therefore have a two piper between the two boilers.

 

[doitall]

So your using either end of a one pipe system. Your new rad is the first on the flow and the last on the return?

No RT read my last post.

 

[doitall]

When you say the old boiler is still working you need to get it de-commissioned as a matter of urgency as you have removed the vent, cold feed etc with the cylinder

Ps, you still need to tell us if the old pump is still being used.

 

[Johnny8718]

When you say the old boiler is still working you need to get it de-commissioned as a matter of urgency as you have removed the vent, cold feed etc with the cylinder

Ps, you still need to tell us if the old pump is still being used.

No! The old boiler is still in the chimney breast and the water runs through it. It isn't wired or connected to the gas.

 

[doitall]

Thats ok then, is the old pump removed or still in place.

Back to your problem you need to fit vents at high level so you can get the air out of both pipes. you can turn one valve off at the rad, vent the pipe then open tha valve and close the other one and vent that pipe.