What is it? Make? Model?
Is there ANY water coming out?
Are any indicator lights showing/not showing?
I would guess you are talking about a shower, probably an instant electric shower, but that's only a guess.
If it IS a shower, there's an excellent site called www.showerdoc.com . The "Fix It" section of the site has a wealth of info, questions and answers from experts.
Ffyugd, December 2021
