Add A radiator *** HELP *** All aspects of plumbing questions and answers, help, tips and information

[danlynch1972]

Can anyone help ?
I added a radiator to an existing flow and return central heating system. I T`ed off of and returned to the pipes just before the last 2 rads on the loop.
The water flow seems to be bypassing the off shoot to my added rad and is only heating the 2 existing rads
Its obvious that the problem is a lack of flow to my new rad but i`m not sure how to solve it. What can i do ?

[chris_on_tour2002]

something very obvious strikes me - bleed it!

[htg engineer]

Or balance the system.


htg

[danlynch1972]

The system hasnt any air in it i can assure you. I have tried to balance the system and the rad is now working however i would like an accurate explaination as to the correct way to balance the system for future reference. Thank you in advance

[Dadwood]

Why not turn off them last two existing rads just to check that you then do in fact get a flow through the new rad? If you dont, are you sure both valves at either end of the new rad are opening and not stuck closed? You could also see if you can turn up the circ pump to the next speed setting and see if this cures the problem. Finally, balancing a system is a very difficult thing to do because the flows are never steady if you have TRV's on every rad. Hope this helps.

[htg engineer]

Balancing is not a diffficult thing to do. If you balanced the system with all but two rads off, then put 6 more rads on - obviously the system wont be balanced anymore.

Basically you set the system up as worst case scenario - which is all radiators/trv's calling for heat. If the trv's shut down one, two, three radiators the other radiators will not be affected.

Balancing - all you're doing is trying to distribute the flow of water evenly, as the water will take the easiest route - the route with the least fricton/restrictions such as bends etc.

To do it properly you need thermometers to establish when there's a 12oC temperature difference between the flow and return to each radiator.

But I would try this first to see if it improves. Go to each radiator and close the lockshield valve fully, then open 2 or 3 turns only. When you restrict the flow in this way the water has no alternative but to find a different route - hopefully the problem radiator.


htg

[danlynch1972]

htg engineer

Thankyou for your help, Dan