Gainsborough shower not heating

[Gary111]

yes theres a little plunger in between the electrics and the shower.
according to gainsborough website it goes down if water pressure is ok.
the model is 9.5 se

 

[Harry Bloomfield]

Unfortunately they do not tell you if the neutral is ok ,or what the voltage actually is. Yes use a multimeter.
By the way Have no idea what that model is ,pic isn't clear.
Yes 230/240 volts is what you should get.

If the neutral is absent, usually you can tell that with the volt-stick lighting up, when placed close to the neutral.