Leaking Strap Boss

[HandSlander]

The strap boss below was fitted about 18 months ago for a Combi Boiler outlet and connected to a pre-existing down pipe which I believe is our upstairs neighbours' (there are 2 flats above) wastewater pipe. Worked fine for a while.

As you can see in the photo there is now leakage coming out - the leakage is from the rubber gasket/plug rather than where the strap boss meets the downpipe, that seal seems solid. I've tried re-seating the rubber but it keeps leaking - my assumption is the velocity of water falling down the main pipe is pushing against the the rubber causing it to come loose.

Any suggestions? I have Plumbers Mait, will that help?

 

[HERTS P&D]

Use this from Screwfix:

https://www.screwfix.com/p/ob1-multi-purpose-sealant-adhesive-black-290ml/784jf

Andy

 

[HandSlander]

Thanks @HERTS P&D I've given that stuff a whirl and will see how it holds up.

At first I did the outside of the rubber plug in all the 'threads' and plugged it back in and gave it a wipe down with paper towels. Jobs a good'un I thought, until it promptly started leaking from the inner diameter and I realised I also should have gummied up the smaller diameter pipe... had to pull the thing out before it cured and redo and it was a proper mess! This stuff is a nightmare to get off your hands, which I can only assume means that when it sets it sets proper...

Will report back if any more leaks otherwise assume this was the fix!

 

[HERTS P&D]

Sorry, I should of told you to wear gloves and pull it all apart then smear all edges and push back together, then wipe away any excess.

It is very good stuff.

Andy

 

[Madrab]

In the first instance I'd be looking to see why it's tracking back, the waste pipe should be far enough into the reducer/boss and at a suitable fall whereby the waste water should run cleanly into the stack.

I must be honest though, I would always use a solvent weld reducer in that instance to ensure it's watertight, those rubber reducers can be a bit of a mare, especially when they get older after long term exposure to UV.