On Jan 19, 9:11 am, ransley wrote:
On Jan 19, 8:24 am, FLSTCI wrote:

My house is a single zone system heated by oil, with convectors in
every room.

Every year at the beginning of the season, I bleed each convecto, to
get the air out.

I have one convector that never seems to want to get hot, (sometimes
it does, but not as routinely as the others). I bled it, and there's
NO air in it. The water, (cold), flows out of the bleed valve with no
problem.

Any thoughts??

Is a convector an upright radiator so when you bleed it its under
pressure or does the same water come out with the system off and its
draining. Does the water flow out as fast when you bleed it as the
others, maybe there is an air blockage somewhere or a valve is off.

Right, if it's a cast iron radiator with a valve, the valve could be
stuck shut. It is still possible to bleed it because it is connected
on the return side, but it won't get water when it circulates. It also
possible that it is a longstanding system design problem--maybe a
monoflow tee is backwards or something. More likely the valve is shot
thought.