combi boiler

[Barry01]

theres a service valve on the heating return and a leak on it from where the driver goes in.
how do i drain it down so i can replace it?

do i isolate the heating flow and drain from lowest radiator?

 

[studips]

nope, if it needs replacing, just drain the lot at any point below the valve to be changed

 

[Barry01]

okay so do i just swith the combi off and start draining from lowest point then when it stops i can change the valve?

 

[studips]

that's it. once done, pressure test, drain a bit off, then add the new inhibitor. you could shut off most of the rads to reduce teh amount of water you need to drain off, but might as well flush all the black stuff out.

you don't even need to switch it off, but you might as well.

oh, and trace the pipework - if it shoots up a wall to do the upstairs before it feeds the drain off (which could be on drops for instance) then you will still have bucket of water in the pipework even after you have drained down.

 

[Barry01]

right okayyy thanks where do i add the inhibitor?