I am trying to pressurise my Worcester 240. It is currently sitting at 1/2 bar. The external filling loop is constantly connected ( we have only just moved in ! ). When I open the valves a little bit of water dribbles from the top of the check return valve but nothing else happens.

If I were to replace the filling loop ( depending on answers ) I assume I would have to turn all the water off at the mains supply?

Barry W, July 2010

If you are looking to replace the filling loop, you would have to turn off the mains water to change the cold water side of the loop.
To change the check valve (heating side), the heating system will need draining/de-pressurising.
When fitting the check valve, ensure the arrow (on the side of the valve), points towards the heating pipe.

Carefree, July 2010