azzar said:
I have the same question. Was this resolved? I have just bought a Gainsborough 9.5 Electric White "select" shower. In the instruction manual it states "An inlet plug must be removed from the chosen inlet port". Each inlet port is a "plastic push fit type". In the middle of each of these ports is a white plastic column with a horizontal slot in it (as if made for a flat blade screwdriver). I had assumed that you just pull this out but do not want to force it. Can anyone clarify the situation?
You're right - the plug has a slot in it so you can take it out with a screwdriver. It's only there to protect the seals underneath on the push fit connector.
To connect your supply, simply push copper or plastic pipe firmly in and then pull back a little (for most push fit's) to lock it. The pipe should be cut squarely and any burr removed from the end before fitting.
Also as mentioned, if it's chrome plated pipe you need to remove the chrome first or it won't grip and for plastic, you "should" use the recomended insert in the end, although it will often work without.