First of all thanks to John Rumm and Set Square for previous related
assistance.

Last night I tried to bleed one radiator and one towel rail both of which
struggle to manage warm when the rest in the house are reasonable temp (both
fed from same plastic 15mm feed).

With the following result:

First of all the towel rail:

Attached hose to top connection and opened each valve in turn.
With only the return valve open I get reasonable flow from the hose.
Closing the return valve and opening the flow valve, I get much less flow so
I suspect the valve is stuck closed(ish).

Next the Bedroom Rad

Tried the same process - remove bleed connection and attach hose.
Same thing occurs, good flow with return valve open, good trickle only when
only flow valve is open.


Presumably this suggests either an air lock or blockage rather than two
blocked valves.
The motorised valve for the heating side is boxed in and not accessible.
But I wanted the heating off before messing last night.

So I have one or two questions:

Does the fact that the heating is off mean the motorised valve is closed and
therefore flow will be lower from the flow side valves anyway?
OR
Would the make up water (which is teed into the return from the hot water
cylinder) pass from the return to the flow side in the rest of the system,
so that flow from either valve on bleeding should be approximately equal?


If this is an air lock, any tricks on how to clear this?
On recommendation, I tried leaving the valve open at both the towel rail and
rad (one at a time not simultaneously) for a while to bleed out the air
lock, but didn't get more than a steady trickle!

So what next?
Any suggestions gratefully received

TIA

Phil