New Hot Water Cylinder - Leaking from coil tapping

[dontknowitall]

I renewed a hot water cylinder around a week ago.

Fitted by about 2 o'clock and filled but I had a leak on the manufacturer's part of the coil tapping. After a couple of hours or so I fixed this with leak sealer. Lower one started leaking but was quite easily fixed.

Then (twin coil) the other side started leaking. More leak sealer applied. Eventually home at 6:30pm. Went back the next day and tried a little more but it didn't really solve problem. Customer not happy and I wasn't happy.

Merchants said they'd arrange a new one.

Today I fitted it and first coil was fine and no leaks on anything else. Just about to fill radiator system (second coil) and the tapping was leaking again. This time I removed my fitting completely and water came out as a small dribble.

I've phoned the manufacturer who said sometimes they loosen in transit. So, I've arranged another cylinder to be made and delivered and merchants have told me to organise an invoice for the manufacturer.

Before I fit the next one I'm going to pressure test it.

2 questions:

1. What pressure is safe to use?
2. Has anyone else had this problem or am I just unlucky?

 

[Gray0689]

Think you was very unlucky never had one leak never mind 2 was not your day mate

 

[diamondgas]

Does it not have it written on the cylinder label, regards pressure? If assuming it's leaking from the 'clean' water side I'd imagine 3-4bar is more than ample coz combi's (dirty-sife) blow-off around 3 anyhoo's that's about 100 foot head isn't it?

 

[Billy Bob Bob]

has it got backnuts? did you try tightening them?

 

[tamz]

Don't test it at anything higher than a bar.
The test pressure will depend on the grade of cylinder. The standard grade 3 has a maximum working pressure of 1 bar (10m) and is tested to around 1.5 bar.
A grade 2 has a 15m max head but you will most likely have a grade 3. It will tell you on the label.

If you are tightening females onto the coil you can sometimes loosen them.

Better to use these (change the stars for scre wfix dot com)
http://www.*************/p/flowflex... Plumbing-_-Flowflex Cylinder Union 22mm x 1"

If you ever get another one leaking at any time, don't waste your time with leaksealer. It never works and if it does it will leak again in the future. Leave that stuff to the BG water amateurs.

Wind the jamb nut back a few turns then wind ptfe pulled to a cord (or loctite 55 is easier) down the back of the jamb nut in the direction the nut will tighten then tighten it up again.

Fixed forever😉

 

[dontknowitall]

Thank you all. It's the female fittings I've had trouble with. Second time I was careful not to over tighten thinking that if they seeped a little then I could try tightening them more once it was filled with water, but to no avail.

I've been using Loctite 55 but will take on board those tips ... and think I'll forget about the pressure test after all!!

 

[Billy Bob Bob]

try ptfe and boss white or ptfe and plumb blue

 

[dontknowitall]

I usually use Loctite 55 and Slic-Tite but will try those if I don't succeed next Tuesday.

 

[dontknowitall]

An update ... new cylinder fitted today and no problems and no leaks with the fittings! I really was beginning to doubt my abilities on this one.

Now a battle with the cylinder manufacturers and merchants to see if I can get some money back.

Many thanks for the help!!

 

[Billy Bob Bob]

glad its resolved dkia at the end of the day you should not need to argue with them if its faulty and dont forget include a bill for you labour to replace it

 

[dontknowitall]

glad its resolved dkia at the end of the day you should not need to argue with them if its faulty and dont forget include a bill for you labour to replace it

They said they'd pay "reasonable costs" so I'm off today to return the cylinders and have decided to try for actual costs involved rather than inflating and accepting a reduced rate. I bet they try to haggle but I'm hoping to be pleasantly surprised.

 

[paulnwales]

they might try and blame you by saying you over tightened it.. i cant remember ever having a new one leak on me. What do they class as resonable, a bag of sweets and a free course prob.