Apologies if this isn't the right place to post this but hopefully someone can help.
Our electric shower (Triton T80xr) has stopped heating our water past a barely lukewarm stage even if it is on the highest setting. As you can imagine it is making taking a shower really unpleasant in this cold weather! It also sometimes makes this knocking sound when water is running.
Does anyone know what is wrong with it and how it can be fixed? Also, who do I contact to fix it? A plumber? An electrician? Help!