Triton electric shower - compression won't compress

[Sadruddin]

I have a Triton shower to plumb in.
Water and electrics are ready to attach, but the manual says use a compression joint.

Two questions?
The manual says nothing about needing a copper pipe, but as I remember you sometimes are required to connect copper pipe rather than plastic

If I use a brass compression joint it doesn't compress, and just slips off.

Have I misunderstood? Is there s different sort of compression joint for this kind of plastic tube?

 

[footprints]

Bet it has a brass olive some are far too hard swap it for a copper olive it will compress much better.
https://www.homebase.co.uk/copper-olives-pack-of-5-15mm_p563802

 

[bernardgreen]

Or should there be a metal insert that fits inside the plastic tube ?

 

[denso13]

Some can be quite loose, just needs tightened up properly

 

[ianmcd]

Or should there be a metal insert that fits inside the plastic tube ?

Not with that type of plastic joint

 

[Madrab]

Have you got an adjustable spanner and grips and are actually tightening the nut properly? Is there actually an olive in the compression fitting?

 

[oilboffin]

To be honest I've spoken to several reps who've told me you can use push on fittings and my shower at home has a push on fitting.Bob