baxi boiler leak, please help

[ballyclover]

Hi there

I have a baxi combi boiler, HE range, about 3 years old.

I noticed a big puddle on the floor and traced the leak to the heat exchange automatic air vent. The little black screw in it was fully open and the water was coming from this. Its stained so looks like being leaking a while. The pressure had also dropped to below 0.5 bar but still working.

I have upped the pressure to 1.5 and tightened the screw. I assume the screw is only to bleed of air and once water comes through it fully bled..Am I right in thinking it should stay closed? If its failed is it ok to leave closed for a few days till a plumber and come are fix it?

thank you

 

[gas112]

Its meant to be open but Wont cause a problem to leave it closed once its up and running, thousands like it dont worry about it

 

[ballyclover]

Cheers, just wasn't sure if the expansion was at fault forcing the water up.If its nothing other than faulty vent I can replace that myself