Upstairs radiator not bleeding

[MattRoz]

Hi there, I've got a tricky problem so hoping someone out there might be able to help me. At the moment our upstairs radiator closest to the boiler isn't heating up properly at the top. I tried bleeding the radiator thinking it was trapped air, but when I open the valve fully, no air comes out.
So then I guessed the pressure in the system may be low, but looking at our boiler there doesn't appear to be a pressure gauge on the system anywhere so I'm guessing this is a gravity fed boiler? I've looked in the loft etc and can't find a pressure gauge. Any ideas what I should do? Should I call a plumber? Or is this something I can fix myself?
It's a valiant Ecotec plus boiler, and there's a big tank sitting next to it.

 

[footprints]

Any tank in the loft?
Look for a vessel usually red about the size of a bucket the gauge and filling loop might be there.

 

[footprints]

Is this your model boiler?

 

[MattRoz]

Hi there, this doesn't appear to be my boiler - under mine I have a single plastic white tube at the rear right of the boiler, and a single metal tube in the centre. Neither seem to have any taps on them. In the loft we have two tanks, one is large, one is smaller but neither seem to have a gauge.

 

[Gasguru]

Hi there, I've got a tricky problem so hoping someone out there might be able to help me. At the moment our upstairs radiator closest to the boiler isn't heating up properly at the top. I tried bleeding the radiator thinking it was trapped air, but when I open the valve fully, no air comes out.

Does water come out?

Sounds like you have a 4 series boiler...open vented so no pressure gauge will be on the system.

 

[MattRoz]

Hey Gasguru - no, there's now water that comes out at all. You can open the radiator valve all the way and nothing - no air, no water.
If I have an open vented boiler - why would there be no water pushing the air out when the radiator valve is open?

 

[footprints]

The small tank is the top up for the system has it got water in it to at least half way?
Push the ball valve down does it start to fill?

 

[cross thread]

probably the air vent in the rad is blocked ,turn off valves to rad ,remove air bleed and clear with a pin refit and close ,then open rad valves

 

[JohnD]

bleed some of the other upstairs radiators. What happens?

 

[MattRoz]

Footprints the small tank is over half way full and when you push the ball valve down it starts filling more. Gordongas I wouldn’t have thought it was blocked as sometimes if I leave it for a couple of weeks you do get a tiny amount of air. But not enough to make water come out, just a bit. And it’s gotten less and less over time so that now when you undo it only a tiny bit of air comes out then it just stops does that still sound like a blockage to you?

 

[MattRoz]

Hi JohnD when I bleed all the other radiators air then water comes out.

 

[JohnD]

have you tried today?

are these other rads as high as the one that doesn't?

 

[MattRoz]

Hi John, the other rads are further away from the boiler if that’s what you mean?

 

[MattRoz]

When I’m bleeding the radiator does it make a difference if the heating is on or off?

 

[MattRoz]

Actually just noticed another upstairs room has started to do the same thing. Opens, let’s air out, then the air sound stops but no water.