How to Drain / Refill my Central Heating ??

[sebsky777]

Very Good Morning from soaking wet London,
Would any one be able to look at photo attached to help me out a bit, how do I drain and refill this system, its New Build , CH , Heat Exchanger, no bleed valves and one very trigger happy amateur (utter) plumber to be.
Cheers have a goooood Sunday
Seb

 

[sebsky777]

Do not touch that it's a safety valve

I just did and i can here water slowly dripping now do i need to call engineer out??

 

[ShaunCorbs]

I just did and i can here water slowly dripping now do i need to call engineer out??

Yes sorry to say

You can see if you can stop it by opening it fully until it click / slams shut it might work but often it doesnt