Draining upstairs central heating system

Hi,
I need to replace my central heating pump upstairs, as well as the isolation valves which don't work. I don't have any drain valves downstairs, but there does appear to be a drain valve on the pipe that's connected to both the hot water tank and the central heating pump. Am I right in thinking that if I isolate the f&e tank in the loft and drain from here then just the upstairs will be drained down, allowing me to replace the pump without water coming out?
Thanks

Can you please take a picture of said valve. Also just have a quick look on top Of the boiler just incase there is one there

Thanks, you are right, there is a drain off valve above the boiler - so if I just turn off the boiler and drain from this, it will just drain the upstairs right?
I have attached an image of the drain off valve upstairs by the hot water pump - this will drain the central heating, and not the hot water tank right?

The one in your picture is from the cold feed to cylinder so would only drain the water inside nothing from the heating. Drain off from above boiler once you have isolated the f&e tank, if you have any tall/towel rail rads upstairs then open the air bleeds on them after couple of minutes of opening the drain cock above the boiler as that water level may be higher than your pump. Just remember to shut the air bleeds before you fill up 😬

Rossy said:

Thanks, you are right, there is a drain off valve above the boiler - so if I just turn off the boiler and drain from this, it will just drain the upstairs right?
I have attached an image of the drain off valve upstairs by the hot water pump - this will drain the central heating, and not the hot water tank right?

Click to expand...

Yes mate. That is correct. Leave the one in the airing cupboard alone. As above it isn’t for the heating. Make sure you isolate the cold water feed to the small tank in the loft by turning the isolation valve off or if it doesn't have one by turning the mains off to the whole house.