Combi Boiler System

[dfox77]

I have a knocking noice through on of my radiators and need to bleed the system which is an Ocean combi boiler .How do I go about bleeding a comi system? 

[Octavius]

Do you need to bleed the whole system?

If so, the only way would be via a water release valve for draining the water from the system, perhaps located near the boiler or near a drain at the back of the house.

I would try just bleeding the knocking radiator first and combine this with adding water into the system to recover the pressure. 

[Clare A]

Please don't! A combi is a sealed system, and you need to drain it down entirely, then refill & repressurise to about 1.5 bar. Don't do it unless you're sure of what you're about. Start frequenting your local pub and befriend an amiable plumber.