connect 22mm to cast iron downpipe

[kermit]

Hi
My 22m overflow / condensation pipe from the combi boiler is attached to a cast iron 4inch? downpipe. This has just been cut and the 22mm siliconed in. This leaks..nae surprise there!
I was hoping to fit a strap-on boss but cannot find one for 22mm.
Does anyone know of a supplier of one or would welcome any suggestions of a better way of connecting the 22mm plastic to the 100mm cast iron.

Cheers

 

[ecowarm]

you can get timesaver strap on boss and use a rubber 11/2" - 22mm reducer

 

[GQuigley67]

is it 22mm or 21.5mm??? you can get reducers just ask your local plumbers merchants

 

[dontknowitall]

I'd try more silicone.

I appreciate it's a cheap fix but if it works it saves on hunting for a fitting or upsetting something somewhere else. If it doesn't work then try a fitting.

 

[turnpin]

Bergin products do a plastic 4" strap on boss available with a rubber sealing washer for use on cast iron stacks and reducers to suit regards turnpin

 

[kermit]

Silicon is non starter I'm afraid, not sure if due to temp (north scotland) or because it never gets chance to dry since cast stack is taking from upstairs ensuite shower etc.
Not sure if its 22 or 21.5, I didnt install, and trying to measure a pipe insitu.

 

[AWheating]

a condense pipe will carry water that will cause corrosion in the cast iron so make sure you have a neutrailser fitted.

 

[stevetheplumber]

ive been told that neuralisers are not to be used anymore anyone know if itss true?

 

[GQuigley67]

as long as its downstream from a bathroom it will be fine, only need a neutraliser if there is nothing discharging above it i believe

 

[GasmanxxxR1]

McAlpine do several condense to cast fittings, just ask in your local plumbers merchents

As GQuigley67 said, as long as something washes down it from above it wont need neutraliser

 

[DAVE01]

hiya check out malpine plumbing Fittings Might be a good idea to trap condensate pipe from boiler going to soil metthane gas there plus the smell factor DAVE01

 

[Mike Jackson]

It's probably also a good idea to check the date of any threads you're replyning to. One hopes that the leak has been resolved by now.