Anyone know what this pipe is..

[pj20000]

I have a slight leak from this pipe near the hot water tank. Anyone know what this pipe does. It seems it can be tightened from the bottom, but I don’t want to mess with things.
It is very slight and not a major concern until a plumber comes and looks at it, but tried goggling and have not idea what this pipe does.
Thanks.

duplicate post

The white pipe? What does it say on the right hand side where it faces the silver pipe? I wonder if it's a magnetic water filter.

The plastic pipe, It says FLOW with an arrow.

Google lens seems to think it's a "Hepvo valve"

I have one of these. It's attached between the pressure release pipe on my unvented cylinder and the soil pipe from my bathroom. Basically if the pressure in the cylinder gets too high then I think water/gas is vented into the pressure release pipe, goes through that white thing and into the soil pipe.

I think it is to stop stuff coming up from the soil pipe (gases etc) and going into the hot water cylinder, or coming out of the tun dish which is above it on my system.

On the other side of where those kind of grip ridges are there should be some raised text that should tell you what it is that you could probably read with a mirror. I can see mine because my valve is rotated slightly compared with yours.

Yes HepVo vlave

https://www.toolstation.com/osma-hepvo-pp-waste-valve-wt/p87210?utm_source=googleshopping%2CRakuten&utm_medium=feed%2Caffiliates&utm_campaign=googleshoppingfeed%2C4639010689668216595274874&utm_content=ShopForward+CSS&ranMID=46390&ranEAID=nz%2FxpRlxjVA&ranSiteID=nz_xpRlxjVA-zJF5HarPOdG.yKMHG5MWng

So slight drip from the top is nothing to worry about?

How easy will it be to replace? Is it a case of unscrewing it and popping a new one on. I don’t mind paying for a plumber as cost is not the issue, just struggling to find someone to come out and do it.
I presume it is “just” as simple as replacing a waste trap on a sink…. or am I being stupid…

Thanks for that, never heard of google lens… Just downloaded it….

If it is the same as mine (and from the web it appears they are used for a variety of purposes) I would be concerned if it were dripping from the top.

From what I can tell about mine, it is supposed to be there only for emergency purposes - ie water only flows through it when something is wrong with the system (too much pressure in my unvented cylinder). Your system may be different.

Do you have a vented or unvented cylinder ?

Just wondering if your heating engineer could help instead of a plumber.