Draining a pressurised system

[Cromeight]

I need to alter some pipework on the central heating system. The boiler is a Vallaint combi but there is no drain valve on the system at all. How can this be done? the pipework to be altered is upstairs.

 

[foxhole]

Release pressure thru a rad bleed valve then you can drain from the bottom of rad via the rad valve.

 

[St0rmer66]

What model boiler exactly? A lot of vaillant boilers have a small bore drain valve on both the flow and return.

 

[Cromeight]

What model boiler exactly? A lot of vaillant boilers have a small bore drain valve on both the flow and return.

Thanks. It's a Vaillant Ecotech Pro 28.

 

[Cromeight]

Release pressure thru a rad bleed valve then you can drain from the bottom of rad via the rad valve.

I've already got the radiator off but need to drain the whole system to cut into the pipework to make some adjustments but there is no drain valve in sight. The only solution seems to be to drain it from the boiler - a Vaillant ecotech pro 28.

 

[St0rmer66]

If you've got a radiator off then why not just drain from one of the open ends of the radiator valve?

 

[Armo74]

If it's a 3/4" valve attach an outside tap adaptor onto the valve and then a hosepipe c/w adaptor.
Don't forget though if the pipe drops are from above and the pipework you are working on is in a different room to where you are draining then that pipework will still be full of water.