Additional radiator not heating

hopeful21

We have just fitted an additional vertical rad in our conservatory. We were advised because of it size our boiler may struggle to get to heat to full potential. It's T'd off from a rad nearby. There is hardly any heat from it. Slightly warm at the top and nothing at the bottom. We have put the main thermostat to max to see if that kicks out any more heat and have turned down a few of the other rads but no change. The rest of the heating is normal and would have thought that if the boiler could not cope the rest of the house would struggle to compensate for the new rad buts it's like it is not recognised on the same system.
Any ideas please?

manda1205

Have you tried bleeding it? I only say this because we recently had a radiator added and we had to go around checking our other radiators for a few days, and it ended up that one upstairs needed bleeding quite a lot as it kept getting cold, consequently we had to add water to the system to top the pressure up too. After a couple of days it all settled and now its all running fine. Might be worth trying though.

Ectophile

At the risk of stating the obvious, have you checked that the valves are turned on at both ends of the new radiator?

mark-w20

Tee'd off..........that's most likely the majority of the problem, if it's off the side of the existing rads flow and returns pipes then the majority of the flow will be taking the easiest route, ie straight on. Better that tees are the other way ie the flow is in on the branch then it stands more chance of flowing left and right.

malc_b

Assuming that it isn't just that the rad needs the air bleeding out then your system needs balancing. Google radiator balancing for instructions.

But basically you need to adjust the lockshield valves so that the water flow is spread out between all radiators. In any house all the radiators will have different pipe lengths and be different sizes. You have to balance them to get the right flow otherwise the nearest one would take more water than the farthest one.

I'd also suspect that a vertical rad is more restrictive than a normal rad so it might involve a lot of adjustment to get the right flow.

ollski

Have you tee'd off microbore pipe (10mm)?, because that won't work. You should get away with it on 15mm by balancing as above.

southcoastrgi

ollski wrote: »

Have you tee'd off microbore pipe (10mm)?, because that won't work. You should get away with it on 15mm by balancing as above.

but that depends how many rads are already being fed by the 15mm pipes

Lgas

Water will take the shortest route - teeing off another radiator is never going to provide the same amount of heat as piping the rad from the manifold or main flow pipe will.