u/Kroktakar

Recently move in a 60's house we have two black water containers in the sealing kne for cold water pressure and the other one to feed the radiators/heating system, the boiler doesn't have the typical key to open it ip and add pressure to the system.

I called a plumber and he opened all the keys, is that correct?

For example the key over the pump, perpendicular to the othe pipes looks like a bypass.

Can somebody explain me which have which purpose and if all of them should be open and how to add more pressure to the boiler?

Maybe is impossible without look at it in person.