Search the forum,

Discuss Cold tank leak from 22mm compression tank connector in the Plumbing Jobs | The Job-board area at PlumbersForums.net

Messages
7
Hello All
My OH's cold water tank has been ever so slightly leaking and I managed to locate the leak...it's a drip coming from where the feeder 22mm compression connector goes through the tank wall.
I've been up and down 4 times now..cleaned everything and replaced the rubber washers..new ones inside and outside. Tightened it hard but it's still got a drip happening from between the tank wall and connector flange.
Baffled.
I haven't used any sealant on the compression connector/tank yet...(cleaned off the old stuff which I guess only made the leak worse!).
Was thinking of using some caravan window sealant that stays sticky forever...but thought I'd ask here first.
What's the best sealant to apply?..that I can easily get hold of...and do I just lather it on?
Thanks in advance.
Neill
 
It shouldn't need sealant. If you must, use something suited to drinking water such as LSX, and definitely not window sealant.

Make sure the hole is properly deburred.

As the seal would be between the flange on the inside of the cistern and the cistern wall, I would be inclined to use a hard washer on the outside or no washer at all on the outside. No point trying to seal the outside as water can run along the thread anyway (unless you seal the thread) If it still leaks, I would even wonder if there is a hairline crack or similar imperfection in the brass or the cistern. Tank connectors are not usually difficult to install.

Could it be that you can't tighten the nut properly because there is sealant on the thread preventing the nut going fully home?
 
Hello All
My OH's cold water tank has been ever so slightly leaking and I managed to locate the leak...it's a drip coming from where the feeder 22mm compression connector goes through the tank wall.
I've been up and down 4 times now..cleaned everything and replaced the rubber washers..new ones inside and outside. Tightened it hard but it's still got a drip happening from between the tank wall and connector flange.
Baffled.
I haven't used any sealant on the compression connector/tank yet...(cleaned off the old stuff which I guess only made the leak worse!).
Was thinking of using some caravan window sealant that stays sticky forever...but thought I'd ask here first.
What's the best sealant to apply?..that I can easily get hold of...and do I just lather it on?
Thanks in advance.
Neill


Hello Neil.

I agree with Member Ric2013 when he recommends Fernox LSX - especially as it will `cure` even when wet.

You must disassemble - clean and reassemble the Tank connector applying the mastic as I describe below - not just smear the mastic around it.

While doing what I describe below make sure that You don`t let any get into the pipework as sometimes `blobs` of this mastic can travel into the orifices of W.C. Floatvalves or get stuck between the Ceramic discs of modern taps.

Please don`t take my next comments as patronising - I am just trying explain `step by step` to help You to get a successful / watertight repair:

Regarding the Tank Connector & washers - the best way for You to fit a connector that has a flange on the inside [inside of the Tank] is to put a washer onto the connector - then wind about 5 turns of PTFE Tape onto the threaded part - just far enough along it to go through the Tank wall, the connector external washer and back nut - apply some Fernox LSX mastic to the internal washer [tank wall side] - push the Tank connector through the hole - apply some Fernox LSX to the external washer [tank wall side] and push onto the connector up to the Tank wall - screw on the Tank connector backnut.

You will have to hold the Tank connector with a tool as soon as the backnut reaches the PTFE Tape to prevent it from turning while you tighten the backnut - tighten backnut until `Firm`.

That `tightness` is not easy to explain as Plumbers / Heating Engineers know from experience and `Feel`.

However to prevent splitting the washers or putting too much pressure on the Tank wall [and possibly splitting it !] you must NOT try to tighten the Tank connector as if it were a Nut on a Bolt.

If You have a Tank connector that has the flange on the outside of the Tank / backnut on the inside the same steps apply you will just be putting the Tank connector through the Tank wall from the outside and tightening the backnut from inside the Tank.

Wipe off the excess [squeezed out] Fernox LSX mastic and although the Tank connector would now probably be watertight if you have time I would advise leaving filling up the Tank for a couple of hours for the Fernox LSX to `cure` although it will continue to cure when the Tank is filled up.

I hope that my descriptions have been helpful.

"Good Luck" with the repair.


Regards,

Chris
 
Try a speedfit tank connector, no glue / sealer etc needed .


Hello townfanjon,

Please don`t take offence to my message as I definitely do not mean to cause any:

I am under the impression that we are trying to help a `DIY Plumber` to seal a leak on an existing CWS Tank connector - without them having to alter the existing pipework in any way.

Including them probably not wanting to have to cut the Copper pipe / possibly extend it or attempt any `Olive removal` or Tank hole enlargement procedures etc.

Regards,

Chris
 
Last edited:
Hello townfanjon,

Please don`t take offence to my message as I definitely do not mean to cause any:

I am under the impression that we are trying to help a `DIY Plumber` to seal a leak on an existing CWS Tank connector - without them having to alter the existing pipework in any way.

Including them probably not wanting to have to cut the Copper pipe / possibly extend it or attempt any `Olive removal` or Tank hole enlargement procedures etc.

Regards,

Chris

Non taken Chris

The speedfit tank connectors are great , I have never failed to seal them first time , as long as the hole is cut properly and the right size , the connector tightens by hand and the copper pipe ( not plastic ) just pushes in , dead easy .
 
Cold water tank plastic?
Wall of tank distorted?
Copper pipe angled slightly downwards?

Then no matter how unlikely don`t discount the olive being the culprit.
 
Non taken Chris

The speedfit tank connectors are great , I have never failed to seal them first time , as long as the hole is cut properly and the right size , the connector tightens by hand and the copper pipe ( not plastic ) just pushes in , dead easy .


Hello John,

Thanks for taking my message as it was meant - i.e. no offence or patronising comments.

Although I am a `Copper man` I am not averse to recommending alternative fittings to suit Plumbing repairs and alterations - even `Speedfit` fittings but in this case unless the cause of the OP`s Tank connector leak is that the hole in the Tank is well oversized for a Brass Tank Connector he would have had to slightly enlarge it to 36mm to suit the Speedfit Tank connector.

And then he would at least have had to remove the Nut & Olive from the existing 22mm Copper pipe [if it had not bitten into the pipe] - IF it was going to then reach the Speedfit Tank connector - it might have been slightly short ?

As We know it would be easy for even a `good DIY Plumber` to get something slightly wrong if having to enlarge a Tank hole / remove an Olive / have to extend a pipe so I wanted to try and explain the `step by step` process to seal the existing tank connector & washers / new washers.

I will admit that I am an `Old Fashioned Plumber` in terms of that I have been using Copper tube and fittings for all of my working life / 52 Years and I have been a Member of the `UK Copper Club` - part of the `UK Copper Board` for about 25 years whose entire purpose is to promote the use of Copper tube and fittings for Plumbing, Heating, Gas and many other uses.

In conjunction with Yorkshire Copper Tubes they provide a lot of the Plumbing Apprenticeship Training information about Copper tube Installation processes and Technical details for Colleges.

As I am now almost at the end of my working life I will definitely resist involving myself in `Plastic Plumbing services`.

I know that You were only suggesting a Plastic Tank connector which Copper tube pushes into.

Regards,

Chris
 
Last edited:

Reply to Cold tank leak from 22mm compression tank connector in the Plumbing Jobs | The Job-board area at PlumbersForums.net

Creating content since 2001. Untold Media.

OFFICIAL SPONSORS

OFFICIAL SPONSORS

Back
Top
AdBlock Detected

We get it, advertisements are annoying!

Sure, ad-blocking software does a great job at blocking ads, but it also blocks useful features of our website. For the best site experience please disable your AdBlocker.

I've Disabled AdBlock