Bleeding radiators help please.

[TigerOnTour]

Two radiators at the top of my house are not fully hot. The Internet tells me they need bleeding. Please can someone advise me on a few things things:
A) The radiators are on the same floor but one is taller. Is this the one I need to bleed?
B) Looking at the pics of the white radiator, where do I bleed it, there is no key hole.
C) Looking at white and black radiators, which key would I need for each?

Thanks!

Turn the heating on and wait for the radiators to heat up. You need to bleed every radiator, starting with the furthest away from the boiler.
Ours just use this type of key

https://www.amazon.co.uk/Draper-24866-Pair-Zinc-Radiator/dp/B0001K9RC6/ref=asc_df_B0001K9RC6/?tag=googshopuk-21&linkCode=df0&hvadid=232020729251&hvpos=&hvnetw=g&hvrand=3093996819916789299&hvpone=&hvptwo=&hvqmt=&hvdev=c&hvdvcmdl=&hvlocint=&hvlocphy=9045255&hvtargid=pla-456436845564&psc=1&mcid=b544dd9d056a3ce898a1a573ece5ce0b

You bleed radiators from the top I think because the air rises. Loosen the little thingy at the top in pic 4 and see what happens?

Don't just do one, bleed them all.

Info here on your weird white one

https://www.reddit.com/r/ireland/comments/ym0n7c/lads_anyone_know_how_to_bleed_these_older/?rdt=52203

Thanks everyone, I thought you only did the highest one. Do I need to bleed the ones that are 100% hot?

I've ordered a mixed pack of keys btw, I have a mixed pack of radiators!

You need a radiator key, they are universal in size and available in any hardware store and Amazon.
When the heating is on and the rads are hot.
Get some kitchen roll.
Go to the rads that are cool at the top.
Put key on valve and turn slightly, you will feel air rush out. Keep the key on the valve as water will follow, as soon as water follows, turn the key back to close the valve.
Use the kitchen roll to wipe up water.
Your rads should now get hot.
You only need to bleed the rads that are cool in comparison to the others.
It is usually the feeder rad that needs bleeding, this is the one that is cooler than the rest when it needs doing.

@PuffinJilly excellent thanks!

Definitely keep the key in and have a towel or similar ready over the valve for when it starts squirting. It can leave nasty stains on your wall

Personally I bleed the radiators when they're cold to avoid scalding when the water comes out. Definitely bleed very slowly even if it means patiently waiting longer. Someone bled one of my radiators years ago, got impatient, opened it up and when the water came it went everywhere.

Don't forget to re-pressurise the system afterwards. Removing air reduces the overall pressure in the system and you will probably need to top up the boiler....there is a handy page on the British Gas website explaining this if need be.

@TigerOnTour you need to check there is good pressure in your boiler first then start bleeding the radiator closest to the boiler. carry on until you get to the furthest away radiator. once all radiators have been bled go back to the tank and fill to the advised pressure level again. the place for the radiator key is usually on the same side as the radiator valve so on the white radiator it would be on the left at the top side. always use a mug or a towel.

Yes, slowly and carefully, and turn the radiator key a minimal amount. If you don't, the water might shoot out, sending the radiator bleed valve flying out of sight, while you wish that you hadn't done this while alone in the house with no phone available, and you wonder where there's a bucket...

Yes agree with bleeding radiators when they are cold. I would turn the boiler off because you'll need to add water to the system when the pressure goes down. And it will also avoid being scalded!

Do NOT bleed hot radiators and turn the boiler off.
PP have given good advice and there are lots of videos on YouTube. I bleed all my radiators at the start of 'radiator' season.
Once you've bleed the radiator you will have to add more water to the system. YouTube search your boiler model and there will be a video showing you how to do it

Good Luck!!