Central heating pump

Have a gravity fed system which has a faulty pump that needs replacing. Only done this a few times and the few times I have done it. I’ve managed to isolate the valves and change the pump. But the pump valves are passing in this one.
If I was to turn of the mains and find a drain off on a radiator (hopefully) and drain will that be enough then to disconnect the pump and replace ?

 

Clean the carp out of the f & e tank before you drain down otherwise it'll all end up in the pipework. Apart from that, yes on you go. If there's any wiring below where the pump is, make sure power is off & you have a bucket handy, there'll be some water trapped even after a drain down. Obv shut the boiler off as well (or at least make sure it won't respond to any call for heat)
And fit some decent valves when you do replace the pump so you/whoever has an easier job next time

 

Buy a couple of pipe bungs and use then to lock off the feed and vent pipes in the F&E tank. That will create a vacuum in the system and should allow the work to be done without much water loss. There will be some water loss so have a bucket/towels ready to catch it. Don't forget to fill the system systematically to avoid airlocks.

 

To answer the question, yes as long as your drain is below the level of your pump