draining down central heating system

[haveagoyourself]

This might sound dumb,but how do you drain down a central heating system if there are no drain cocks fitted on the rads.

[EliteHeat]

Take the smallest downstairs radiator off after closing both valves. Attach a 3/4" connector and garden hose adaptor to one of the valves, fit hose and there you go.

[haveagoyourself]

Thanks EliteHeat.What water supplies will i also need to turn off ?.

[EliteHeat]

If you do not have a sealed system, just use a bungy to tie up the valve in the expansion tank in your loft. It will be the smaller of the two tanks which are (probably) up there.

[haveagoyourself]

Many thanks again.I only have an emersion heater and downstairs hot water boiler (not a Combi).

[JohnD]

And put one of these on at least one of your downstairs radiators, once you've drained it.