Cylinder problem

[Scottwood75]

Hope this is the right forum for it.

My brother has just bought a new house with an oil fired boiler and has had some problems, firstly, the taps were all loose and I changed them, then we noticed the return from the cylinder was leaking.

Attempted a repair but it was badly corroded so we got a replacement and the fittings needed. Made up new connections for the flow and return and with an inch male to 2mm compression elbow, started the cold feed.
Used the existing pipework and olive for the 22 side and taped up the male thread. tightened well but upon filling it leaked. So drained down and took it back out, cleaned the old ptfe off and rewraped it up with a little more and on the plate by the nut used a bead of liquid ptfe.

whipped it in, tightened, and reinstalled the cylinder. Filled fine and central heating side did too. bled the rads and everything, then started the programmer to call for hot water and heat.........

Then the cold feed leaked again, from the same place. I'm only in training at the moment and have pretty much done everything I can think of. Any ideas please?

That coupled with the fact my brothers boiler wont start was very frustrating yesterday.

 

[Puddle]

If I read your post correctly,you are using olive compression fittings to attach to cylinder,you need special connections to cylinder that take you to 22mm pipework,either cylinder unions or female to 22mm couplings
Also if you are doing a compresion joint up the seal is the olive to the fitting,the thread just pulls and keeps the olive joint tight therefore you do not need to put ptfe tape on thread,only use ptfe tape on threads when using male or female joints

 

[Scottwood75]

Sorry guess my post wasnt clear. the cylinder has a female threaded boss and the elbow is a 1" male thread. thats where it is leaking from. the other side of the elbow is the 22mm compression with just an olive.

 

[Plouasne]

Sorry guess my post wasnt clear. the cylinder has a female threaded boss and the elbow is a 1" male thread. thats where it is leaking from. the other side of the elbow is the 22mm compression with just an olive.

Either make a "grommet" with Hemp and Boss White or thats Interdit now use PTFE tape, or fit a "Klingerite" washer

 

[Puddle]

sorry scottwood,just was not sure about description

as Plouasne says you are best using a jointing compound in joint either hemp and boss white which would be best or you mention you have some ptfe paste
apply over thread then rap tape overlaping,then apply paste again on top on tape and thread fitting on

 

[Scottwood75]

Thanks for all the great advice, its been sorted now, it turns out that the surveyor that did my brothers house is either blind or completely incompetant. As mentioned before about the oil boiler.........Its leaking the engineer smelt it the second he walked in the door. Combine that with the leak from the supply stop valve right next to it and it almost makes the leaking cylinder he missed kinda trivial. They are complaining to the company used as the surveyor said all was fine.

 

[Winston]

Use Gas Paste I have never had a leak from it, and I love the smell of it

 

[Bernie2]

Is the house a new build or an old house new to you? If so it might be imperial pipe.