Why is leak occurring

[Sudnik]

Thanks for input, newly installed concealed mixer shower valve, the hot water input keeps dripping but as can see it forms from the valve, rather than the connection point, tried PTFE, jointing compound on joint, and switched out the compression for a new push it alternative but it keeps forming.
Hiss is heard too,
Thinking could be a defect in the mixer valve rather than connection,
Thanks in advance

 

[blup]

Over or under tightened , probably the former as it looks to be a hand tight fit plus a quarter turn. If it’s a compression fitting no ptfe is required

 

[thomp1983]

That looks like if you remove the larger compression nut and pipe the section remaining with the smaller hex section can be undone and removed, if so it's probably leaking along those threads and some ptfe on there should cure it.

 

[Alec_t]

There seem to be several water drops elsewhere on the valve body. Are you sure your assumed leak is where you've arrowed?

 

[Munroast]

That looks like if you remove the larger compression nut and pipe the section remaining with the smaller hex section can be undone and removed, if so it's probably leaking along those threads and some ptfe on there should cure it.

wrap the ptfe around the olive will get a better seal - putting it on the threads is just to make tightening easier, and in many cases causes problems with over tightening

amazing how many people don't know what ptfe tape is for -

 

[thomp1983]

wrap the ptfe around the olive will get a better seal - putting it on the threads is just to make tightening easier, and in many cases causes problems with over tightening

amazing how many people don't know what ptfe tape is for -

Read what I wrote again, the section with the pipe the ptfe will go round the olive but there looks like there is a second reducer section screwed into the valve body which appears to be the source of the leak, that won't have an olive and will require ptfe on the threads that screw into the valve body.

 

[denso13]

That looks like if you remove the larger compression nut and pipe the section remaining with the smaller hex section can be undone and removed, if so it's probably leaking along those threads and some ptfe on there should cure it.

This. Remove the threaded fitting from the shower valve, apply PTFE to the threads and refit. Can't see any on it, not to say there is none.

 

[Munroast]

Read what I wrote again, the section with the pipe the ptfe will go round the olive but there looks like there is a second reducer section screwed into the valve body which appears to be the source of the leak, that won't have an olive and will require ptfe on the threads that screw into the valve body.

you mean between these two, yes if it is a join?, i agree ptfe might help there

 

[Madrab]

Yes - it will usually be one of these that's in there



Undo the compression nut and disconnect the supply pipe - then unscrew the male coupler out of the shower body tapping - apply a suitable amount of PTFE tape or cord around the male end threads and then refit - then refit the supply and try that - may need a few turns of tape around the compression olive, now it's been reused, just as a belt 'n' braces

The other thing I would say is that compression nut seems to be very far down the couplers threads, definitely an olive in there that isn't over compressed?