HELP need to up boiler pressure!

[jogger8000]

hi thanks for coming. I really need to know if this red tap and pipe is to up the pressure on my boiler as its getting low. Ive lived in my house 3 years and never done it. Please help!

 

[cjg]

no its not... look for a silver flexable pipe it should have two taps on. open one the slowly open the other water will then go in . no more than 1 bar.