Draining and hot water system via radiators

[jiffter]

I want to drain my entire heating and hot water system to change an indirect hot water cylinder and change some piping as well. The boiler is a nightmare to work on as there is no drain cock or any other means of draining the water out of the system other than releasing the lock nut under or above the water pump. Can i drain the system by letting the water out via the radiators as well as using the drain cock on the hot water cylinder?
many thanks in advance.

 

[Spike295]

If you have a small rad that is easy to get to, isolate the rad valves, take off the rad, attach a hose pipe to a valve then open the valve & drain it from there. When its drained stick the hose on the other valve & open that too. When its all drained replace a valve for a valve with a drain off point.
The quickest way to drain a cylinder is to isolate the cold feed to the CWS tank, open hot taps to drain the CWS tank, take out the top tapping of the cylinder, drop in a 3foot length of 15mm copper tube with a hose attached, then lift the pipe up an inch from the bottom of the cylinder, put a pipe clip on to stop it dropping back down then take your hose to the nearest drain & suck on it....it'll syphon out in no time.

 

[jiffter]

Many thanks for the reply, much appreciated.