Removing Rads from a Combi system

[Gammy leg]

Hi,

I need to remove two rads from my combi system so I can knock down a wall in my upstairs bathroom and then get the whole room re-plastered.

• The rads are situated half way up, and are on either side of the wall that is getting removed.
• They are highest two rads in the house.
• They are connected in series with feed & return pipes coming from above through the loft.
• The boiler is downstairs in the kitchen.
• The pipework in the bathroom is copper, but once in the loft it reverts to JG Speedfit.

I plan to switch off the boiler and drain down the water in both rads and remove.
I then intend to cut both supply and return speedfit pipes in the loft and put in a loop so that the water will still flow but only to & from the boiler.
Once completed, I'll re-presurise the system up to 1 - 1.5bar at the boiler.

My question is that as I'm likely to introduce a fair bit of air into this circuit while i'm doing the work, will I have to bleed the system, and if so how, or will the boiler take care of it when the central heating finally switches back on sometime in October?.

Thanks

 

[terryplumb]

Are you not going to have any radiator at all in the bathroom ? As well as draining the two rads ,you will need to drain the system ,at least to a lower level than the pipework you intend to work on .after repressurising you will likely have to bleed some rads ,boiler should have its own auto air bleed valve.

 

[endecotp]

They are connected in series

Are you sure? That would be unusual.

I then intend to cut both supply and return speedfit pipes in the loft and put in a loop

If you mean a connection between the flow and return pipes, then no you don’t what to do that if it’s a normal modern system.

 

[Gammy leg]

Are you not going to have any radiator at all in the bathroom ? As well as draining the two rads ,you will need to drain the system ,at least to a lower level than the pipework you intend to work on .after repressurising you will likely have to bleed some rads ,boiler should have its own auto air bleed valve.

The pipework I'm working on is in the loft at it's highest point.

Once the wall is removed and the bathroom is re-plastered & tiled, one of the rads will be going back in, albeit in a different location.

 

[Gammy leg]

Are you sure? That would be unusual.


If you mean a connection between the flow and return pipes, then no you don’t what to do that if it’s a normal modern system.

Ah, yes, just checked again and they're in parallel. The pipework is a bit tight in the cupboard so not too easy to spot.

What is the problem with connecting the flow and return pipes? It's the same circuit minus two rads.

 

[endecotp]

What is the problem with connecting the flow and return pipes? It's the same circuit minus two rads.

The hot water from the boiler will flow through this connection and not through the other radiators.

Why do you think you need to connect them?

 

[Gammy leg]

The hot water from the boiler will flow through this connection and not through the other radiators.

Why do you think you need to connect them?

I see, I assumed that that was what I should do. Should I just blank off each one until I'm ready to reconnect the rad once the bathroom is finished?

 

[endecotp]

Should I just blank off each one until I'm ready to reconnect the rad once the bathroom is finished?

Yes.

Your question about trapped air is interesting; maybe someone else will comment. I can imagine that you could get noises due to the air resonating. Not a big problem if it’s temporary.