Drain valves Baxi combi

[Smk80]

Hi all

I am looking to drain down my radiators but there is no drain valve on any of my radiators. There are however what appear to be two drain points on the flow and return pipes coming out of the bottom of my Baxi Combi boiler - photos attached. I am assuming these are the drain valves for the system/rads?

If they are do I drain from the flow or return? Any advice much appreciated

 

[terryplumb]

Drain both. I assume all radiators are at a higher level than the floor that the pipes disappear into.

 

[Smk80]

Drain both. I assume all radiators are at a higher level than the floor that the pipes disappear into.

Yes the boiler is in the garage and pipes are lower than the ground floor in the house

 

[terryplumb]

All good to go then.

 

[Smk80]

All good to go then.

This might be a silly question but do I need to turn off the mains water supply when draining? The boiler has two knobs that turn to let water back into the system so they seem to stop any water entering unless turned.

 

[terryplumb]

No ,mains water doesn't need turning off. Electrically isolating the boiler would be prudent.

 

[Smk80]

No ,mains water doesn't need turning off. Electrically isolating the boiler would be prudent.

Thanks much appreciated