I am replacing my shower mixer for an unequal system and it is saying if the cold pressure is above 400kPa don't modify it, use the red nozzle (factory fitted) but below 400kPa replace the nozzle with the blue nozzle. I'm in Avondale, Christchurch so what pressure do we operate on here - thanks

Linkback: https://www.plumbers.nz/q-and-a-baths-and-showers/64/methven-shower-mixer/579/

Hi, pressure is not necessarily area related. In most cases pressure will be under 400KPA but to be 100% sure I would advise getting the pressure tested. Olso to be aware of is the fact that if your pressure test results with 300 - 400 kpa make sure you get a limiting valve installed as pressure will change at night time.  hope this helps