Does bleeding a radiator reduce boiler pressure?

How long do you bleed a radiator for?

What happens if you don’t bleed a radiator?

Which radiators do you bleed first?

What happens if you bleed a radiator with the heating on?

What key do I need to bleed a radiator?

How do you bleed a radiator without a key?

Do you bleed radiators when the heating is on or off?