Fitting an Airvalve / bleeding point in central heating

[FluffyWaffles]

Hello, total plumbing noob here.

I have a sneaking suspicion that the pipes in my house that run all the way to the attic are full of air (picture attached of pipes). These are the pipes that used to be fitted to an older hot water tank which was removed and replaced with a combi boiler- but the pipes are still there and are still connected to the central heating.

I wish to install a valve onto one (or more) of these to release the air and I think the pipe is 22mm thick (I'm not a plumber by the way so please use plain english!). I saw screwix is selling bottle air vents but these look like they need to be screwed onto something and are 15mm connections. Is it as simple as fitting a 22mm to 15mm reducer and then attaching the valve to bleed the air or is there something im missing?

 

[Stigster]

Both those bits of pipework in your picture most definitely are about as good as an air-trap can be. If the redundant sections of pipe cannot be cut right back to where they tee off then yes, air bleed vents will do the job.

The one on the right looks like 22mm and the loop on the left looks like 22mm reduced to 15mm. However it can be difficult to be absolutely certain when looking at pipework in pictures. The best practice here would be as I say to remove these pipes but I appreciate that is not always practical, especially if it involves breaking into boxing or ceilings or whatever, especially as a DIY project.

This type of pipe is sized by it's outside measurement so take a tape measure or rule and measure the pipe to be sure of the sizes. After a partial drain down you will be able to reduce the 22mm (if that's what it definitely is) to 15mm and add a little stub of 15mm tube and add a vent there. For the one on the left, it looks like there is just about enough room to cut in a tee and again add a little stub of 15mm tube to connect a vent to. You can go with either a manual bleed vent or an automatic vent. Automatic vents will save you having to periodically manually bleed the pipework but they are a little more prone to leakage, or rather weep after a few years use but they are an acceptable solution. Manual vents obviously require occasional manual intervention but are less prone to weeping after years of use.

I would solder them but for DIY there's nothing wrong with using compression fittings.

Measure those pipes to obtain definite sizes and we can go from there.