Unvented cylinder leak

[Powderkeg]

Hi all

A week ago I had an unvented pressurised hot water cylinder fitted (an Ariston Primo 210) by a fully qualified local plumber. He did a great job with the install, but unfortunately a leak has developed around the upper immersion heater. My plumber has been back to rectify the problem by draining the system and refitting the heater with a new seal, but to no avail, as the leak has started again.

Does anyone have any idea how to fit the heating element without it leaking? More importantly, why is it leaking in the first place?

I have uploaded a pic of the cylinder to illustrate..



My eternal thanks to anyone who can help with this, as myself and the plumber are both stumped.

 

[NickH]

This really isn't your problem, get the plumber back and he will have to get it sorted. Either the immersion/seal is faulty or you have a fault on the cylinder, either way he will have to put it right. Dont let him shrug his shoulders and walk away.

 

[Powderkeg]

Thanks Nick - definately not planning on it, just trying to satisfy my own curiosity really! Thing is, the cylinder he replaced also leaked, though I dont think from the same place. I think youre right in that the seal is faulty - do you think I just need a new immersion element, or does the whole tank need replacing?

Cheers

 

[stevetheplumber]

new seal ptfe tape and lashings of boss white shoulkd do the trick

 

[Powderkeg]

thanks Steve - but we tried that. Is this a common problem then? Seems wierd to me that a manufacturer wouldnt just make elements that fit with a minimum of fuss. Hey ho

Just thought of something else, the lower of the two immersion heaters appears to be fine, so could it be that the seal on the other one is faulty?

 

[sonray ltd]

if the plumber takes it out and checks the cylinder for damage and the fibre washer for damage theres no reason why it shouldn't seal on its own.

 

[leakylea]

were the emersions factory fitted ?
could the plumber of cross threaded the emersion ?

 

[Powderkeg]

thanks guys. All parts are factory spec. Sonray - absolutely! thats why we are so stumped!!

 

[sonray ltd]

try 2 fibre washers or abit of jointing compound

 

[NickH]

Take the immersion out, clean all the gunk off and then screw it in without a washer. Check to see that the two mating surfaces come together paralell. It could be that the boss has been badly machined and is out of true.

 

[Powderkeg]

Cheers guys - will give it a go and report back

 

[sasik]

I think your plumber cross theareded and damaged the element thread when he fitted it. And I bett he knows it but he won't admite it! I think you should ask some one els, some one you trust to come and have a look at it and tall you what is the problem. But remember no matter what you do, you payed for a profesional person to fit a new cylinder in your house make sure they complet the job before they leave!

Thanks

Sasi

 

[McNaught]

Hi

I think I have the same problem. My cylinder has only started leaking recently after two years. I'm not a plumber and have tried to tighten the nut at the back of the top immersion control, as you have described.

I was wondering if I could replace the seal without draining the system. It's a new house , three storeys and a very big system. My plumber's having a beano in Thailand so I can't get him back at the moment.

I think the leak is getting worse and I am catching the drips, and filling a container for this, a bit quicker each day. I'm worried it may go completely.

Suggestions?

Bryan.

 

[unguided1]

just a thought, are you positive that the cylinder you have is a primo and not a classico.
The classico is glass lined and prone to heat damage?
Regards
Mike

 

[HTB]

LSX would be my preferred sealant for this.

 

[justlead1]

Hi. I seem to remember that a a few unvented systems i have come across used an "O" ring as opposed to fiber washer on the immersion heater, perhaps this is worth a try. What ever method is employed it may need to come out in the future. Good Luck

 

[GPS164]

I know its stating the obvious but its possible that the heating element has a fault from factory production...it happens...

 

[McNaught]

Thanks for the response.

We removed the heating element (behind control) and found that the copper tube had a pinhole at the end, which had been soldered, presumably in the factory. This could be a common problem so check yours.

We built up the solder again and refitted, and no problems.

Factory fault or design flaw?

Bryan.