Bleeding radiators but no water, no air!!!

[JohnEllicottington]

Hi Now that winter is on its way I decided its time to think about switching the central heating. I have a combi boiler and it is located in the garage. I like to bleed all the radiators before I turn the central heating on. I live in a town house (Three floors) and all was going well until I reached the top floor, where two of the radiators will not expel any water or air? I have left the bleed valve open for quite a while but nothing. Has anyone an idea of what is wrong? Thanks in advance for any advice. Johno

[Lobster]

Only just?! You must be single then!

David

[Martin]

Is it a sealed or open system?

If sealed then what's the pressure of the system sounds like zero and it needs topping up.

If open then is the header tank full?

Martin.

[JohnEllicottington]

How do I tell? The combi boiler is in the garage and there are no external water tanks in the loft or any where else in the house as far as I know.

There's a pressure valve on one of the pipes in the garage, near the boiler, and its currently reading around two.

As above, I do not think there is one.

[Dave Jones]

On the front of the combi, there should be a dial, which should have a red marker at around 1.5 to 2 bar, the black needle needs to be at this point. Under the combi should be a flex hose with a tap at each end, turn taps on to pressurise system (close all bleed valves) or sometimes internal with the use of a key. Check instruction manual!

[Set Square]

Sounds like you might benefit from reading Ed's excellent Sealed System FAQ at

[daddyfreddy]

Are the isolating valves either side of the radiators open?

[Ruski]

Try closing the return flow LSV and see if this forces air to escape/fill the rad with water. Worked on mine the other day.

[JohnEllicottington]

the rad with water. Worked on mine the other day.

Thanks, I will try that and let you know the outcome.

[Ed Sirett]

See the SealedCH FAQ.