central heating system drain

[greazer]

i want to replace radiator in upstairs bathroom with heated towel rail and new valves, so need to drain vented system, but cant find any drain off valve on any of the rads downstairs, help please?

thanks.

[DEEARR2]

Have you checked outside for a drain point. ACOP is to install an external drain point.

[htg engineer]

DEEARR2: Why would there be a drain point outside ? i've never seen one. It's a vented system so if you meant a pressure relief valve - there wont be one, and the PRV is not meant to be used for draining the system, unless in an emergency.


Turn off cold water, isolate one radiator (smallest downstairs) undo nuts and lift radiator off - connect hose to radiator valve, open and drain. Use this opportunity to fit a radiator valve with drain point incorporated.

htg

[DEEARR2]

Htg Engineer, drain point outside for draining the heating system usually located at the lowest point in system, pressurised or vented. was not refering to PRV.