Radiators

geordief

Wondering what could be the problem with my radiators.

They are downstairs and so I doubt there would be an airlock.

When I open the bleed valve on the top (with the inlet and outlet valves closed ) there is a good influx of hot water when I open one of the valves.

When I close that valve and open the other ,there is a good influx of cold water (from the other direction now) that comes out of the open bleed valve.

But when I close the bleed valve (maybe not a "valve";it is a small round screw that goes into to top of the radiator) and open both inlet and outlet valves the radiator does not heat up.

Any ideas ? Could there be a blockage in the pipes? A blockage in the radiator even though it accepts water from either direction?

youtheman

I would do some more investigation.
Run the system normally and see how many radiators are 'hot' on the inlet pipe and slightly cooler, but still hot, on the return pipe.
To rule out a blockage shut all inlet valves to every radiator, bar one, and see if it gets hot on both inlet and outlet pipes. Repeat for each and every radiator. If a radiator gets hot when it is the only one open but then gets cooler when you put them all on line then this means your system needs to be balanced (remember the water wants to take the easiest path back to the boiler).
Not sure if it is a sealed system or not. But make sure you system is either pressurised or the header tank in the attic is full.