hot cold hot cold shower All aspects of plumbing questions and answers, help, tips and information

[lowey]

my friend has a flat, they put their shower (mixer tap) on hot and its scoulding hot, hey turn it to cold and its freezing, they put it in the middle and it goes hot and then cold constantly vice vera. they have been told by a plumber its some one in the building turning a top on theres nothing wrong with the mixer, piping etc, yet she has swore she has tried testing most times of the day. any suggestions?

[rosebery]

Thermostatic mixer? If so they need a new cartridge I'm guessing.

Bog standard mixer? Sounds like unbalanced supplies if gravity system. If combi boiler I wonder if the demand is greater than the boiler can provide. If thats the case then they should have a thermostatic mixer.

Cheers