Valliant boiler VCW T3W - how do I increase pressure?

[DougSussex]

I've got a 15+ year old Valliant TCW T3W boiler. The pressure has dropped to below 0.5 and I need to top it up. A few years ago, I watched a plumber do this, but now I can't remember what he did! There are two taps on the pipes under the boiler - one looks like an outdoor hose tap, the other looks like a red octagon with "open" and "close" on it. I recall that it has something to do with opening/closing one or both of these taps. Can anyone help!!! Simple language please - plumbing is not my thing. Many thanks

 

[ChrisR]

In principle you just open both taps and let the pressure slowly rise to about 1 then close both taps.

But only of there's a flexy hose joining the taps together...

 

[chrishutt]

Look in the FAQ topic above.

 

[DougSussex]

Ok - I've opened both taps, but nothing happens - no sound of water flowing, nothing. Any suggestions?

 

[ChrisR]

suggestions

Plastic tap tab turning but not the metal bit underneath?

 

[Agile]

If there is a non return valve fitted as there should be then they often get bunged up with dirt.

You may need professional help!

Tony

 

[maka2k2]

agree with Agile, you might even need a new non return valve, its not a big job for a professional