Tank connectors - apply sealant to washers?

[scubapete]

It's an interesting topic. Not a lot you can do to deal with a problem if you're on holiday. Best you can do is take preventative measures. Which includes turning off the stop cock and Symptoms recommendation of soldered joints in the loft.

I also had a leaky fibre washer from the mains feed to CWC this summer. First thing I knew about it was when I noticed the paint peeling from the door frame directly below. Easy to fix, but how do you prevent this one? Replace the washer every few years? Put the CWC in another tank with its own overflow?

(Please excuse the ramblings of a novice)

 

[hi-spec plumbing heating]

you can't prevent the leaks happening.
people get very nervous working on their water systems, but only due to not understanding them.

 

[scubapete]

So, I went to do up the compression joint and realised you need a special tool to hold the back of the connector in the tank - D'oh!

So, I just bought some polyplumb hand tighten connectors and guess what - they leaked.

Have applied loads of sealant and will await the result tomorrow.

Does anyone know if the leak could be caused by the hole in the tank being too big? I drilled a 29mm hole.

 

[hi-spec plumbing heating]

>I drilled a 29mm hole.

if thats for a 22mm fitting should be ok.
did you clean the edge of the plastic tank where you cut the hole ?

 

[scubapete]

Yes, made sure all the loose bits were cleared away. I actually have two of them exactly the same and they both leaked when the water level got about half way up the tank.

Will the sealant be ok constantly submerged. Does it dissolve or degrade over time?

 

[Balenza]

scubapete wrote

Does it dissolve or degrade over time?

It will dissolve over time m8. Its what its designed to do when water makes contact with it.
Best keep your scuba gear handy when you arrive home some evening to a flood.

 

[scubapete]

Great.

Anything else I can use? A plumber, perhaps.

 

[scubapete]

Ah-ha! What about aquatic silcone sealant?

 

[scubapete]

I feel I ought to bring this sorry saga to a happy ending and try and get my first two page post into a third page..

Spoke to polyplumb technical help and he said the washer goes on the outside of the tank, but he would always fit it with another rubber washer on the inside. Strangely though he couldn't tell me what diameter hole to cut. I did a 29mm but I think 27mm would be a better fit.

Anyway, no leaks and I have hot water again.

The wife can finally wash my underpants.

 

[JohnD]

try and get my first two page post into a third page..

try to remember the number "14"

 

[croydoncorgi]

the washer goes on the outside of the tank

Huh??!!

This defies explanation! If the washer is compressed between the flat flange and the tank wall INSIDE the tank, NO leak can occur.

If it's on the outside, OK - no leak can occur between the tank wall / washer / backnut BUT it will CERTAINLY leak along the threads inside the backnut and drip out between the backnut and compression nut. (Of course, you MIGHT coat the whole thing with some goo and seal the threads that way - but why bother??? Washer on the inside works for me!

 

[scubapete]

Well i did ask him to confirm the outside twice more after he first said it.

Don't forget this is a plastic pushfit so no compression nut. Also the thread doesn't make it all the way to the flange, the final 2-3mm is just solid plastic.

I put one on the front and back so I cannot empirically say whether just having one on the front is sufficient.

I know for certain that just one washer on the back leaks. After your comments croydon, I'm guessing it leaked through the thread.