Water pressure after shower and bath refitting

[thelongwayhome]

Not sure if this is the right place to post, but hoping someone will be able to help!
Had a bath and shower fitted yesterday. Fine, waited the 24 hours to use it, and the water pressure is awful, it's not enough to wash the conditioner out of my hair. What could have gone wrong to cause this? Can't get in touch with the fitters as it's Good Friday, and I'm hoping it's something I can fix myself. (Fingers crossed!)

Some showers and taps come with a pressure reduction fitting. It may have been left in.

You could try opening the stopcock further, it's generally found under the kitchen sink

Do you have a low pressure gravity feed hot water system from a tank in the attic, or a modern pressurised pumped system, OP?
If you have the former, and the fitter assumed the latter, he may have used modern narrow bore piping and the resistance is too high to allow a fast enough flow with just gravity.
Hopefully not, and it’s just a matter of opening the stopcock a bit further, as PPs suggest.

You will need an adjustable spanner. On the tap remove the spray nozzle, there may be an extra piece that can be removed. On the shower hose check both ends.

Remember to tape the fitting to avoid damaging the chrome with the spanner.

Please post a photo of your shower mixer and the squirter.

Do you have a hot water cylinder? What colour?

How does the pressure seem from the basin taps?

Pressure from basin taps and all other taps seem fine, just checked and stopcock is fully open. I'm actually not sure Babdoc but my dad will know, and he should be able to have a go at seeing if this removable piece is there (I'm too wary of doing anything myself, I think I'm cursed ) when he comes over to do some odd jobs later today.
I shall attempt a picture Piglet, just having a very late breakfast!
Thank you for all your replies

@thelongwayhome

my excitement and anticipation are becoming overwhelming

@PigletJohn sorry for the delay, forgot about the thread, half term chaos and all that. Fitters are coming out to check it all now as my dad didn't want to do any damage that could be blamed on us. Fitters have said the pressure should not be any different to previous levels so are going to attempt to rectify it. Totally exhilarating situation, obviously

It could be an airlock in the pipes. Turn the taps on and leave on. Then locate your stop tap (or isolation valve if one has been fitted on the pipes leading to the bath and shower) and wiggle it on and off a few times then return to the on position. The water should then splutter a few times as the air comes through and then start to pick up.
Works for us every time the water goes off during a burst main in the area.

(Am also an ex water company employee).