system with no drain

[Alfies Revenge]

What is the best way to drain a heating system with no draining point.

 

[sooey]

Pick a downstairs rad, best in the kitchen were there's hopefully no carpet. Close both rad valves, undo the big nut connecting one of the valves to the rad and catch the water from the rad in a bin bag or something. When the rad is empty disconnect the valve and turn it a little on the pipe, then connect a hose to the valve with another rad union and open the valve. This will drain everything above the valve but won't drain other downstairs rads if they are drop fed.

 

[ollski]

Or cut a self cutting tap in somewhere out of the way.