central heating (flow) to cylinder is leaking through nut.

[givemestrength]

I have a cylinder that is leaking through the nut (central heating flow) which is connected to the cylinder. I have tweaked the nut but it is still coming through.

Please can some give me advice on how to stop.

If i have to undo nut is there a washer that i can replace?

Am i also right in thinking that i would have to drain the central heating and the cylinder down?

Is there anything else to be aware off?

Help appreciated.

Thanks

 

[seco services]

if its an old cylinder poss it need a new cylinder.
quite a common place for them to go around the coil fixings.

 

[Elkato531]

If the leak is on the primary circuit ie the pipes carrying heat from the boiler to the cylinder, you will not need to drain the cylinder, only the heating system.

It then depends on what type of fitting you have onto the cylinder. If its a compression you can usually get away with undoing the nut and wrapping a couple of turns of PTFE around the olive before retightening. If the leak is from the threaded fitting onto the cylinder you will have to remove it, wind PTFE around the cylinder tapping and remake the joint. If you have a tapered cylinder union you can try a bit of jointing compound on the sealing surfaces.

 

[givemestrength]

Thanks for responses. My logic is telling me that if it was coming from the coil fixing onto the cylinder if i loosen this then the water from the cylinder will come out if not drained down. Is this not correct or am i missunderstanding how this works.

 

[seco services]

if its coming from the cylinder due to corrosion then yes your dhw start leaking if its only a loose or bad fitting on the primaries to the coil
will still need to be drained if your going to release the fitting.

how olds the install?
does it look like corrosion is it green ?
or just a bad fitting needs resealing.

 

[givemestrength]

Install not too old. fitting clean but needs resealing. Sorry a bit unclear (being a bit thick) if i need to reseal do i need to drain both the central heating and the hot water in cylinder befor undoing the nut?

 

[seco services]

if its only the fitting onto the coil then only the primaries need draining not the dhw in the cylinder.

 

[givemestrength]

many thanks. Was just trying to understand how the internals work. I know there is a coil in there but thought if i undid the nut to this it would release the stored hot water as well.

 

[seco services]

no just the water in the primaries.

 

[kevplumb]

View media item 11263

 

[seco services]

View media item 11263

and heres one he done earlier.

 

[givemestrength]

Cheers this helps.

 

[Goldspoon]

fitting clean but needs resealing.

Wrap a few turns of PTFE tape around the olive on the pipe that inserts into the cylinder then tighten back up.