I've got a Trevitherm 300 built-in thermostatic shower mixer that I installed about 18 years ago. The last couple of showers have only managed to get luke-warm so I have had a look at it this morning but can't get the thermostatic control cartridge out to check the screens and O-rings. It simply won't budge.
What I notice is that the bit inside the cartridge is not moving very freely (in the directions of the red arrow). I presume that the control knob/shaft pushes it in to alter the temperature one way, and it springs out again to change the temperature the other way.
Am I correct in assuming that because it won't travel freely, it is getting stuck on a 'colder' setting? And if so, is there anything I can do to remedy the problem without getting the cartridge out?
What I notice is that the bit inside the cartridge is not moving very freely (in the directions of the red arrow). I presume that the control knob/shaft pushes it in to alter the temperature one way, and it springs out again to change the temperature the other way.
Am I correct in assuming that because it won't travel freely, it is getting stuck on a 'colder' setting? And if so, is there anything I can do to remedy the problem without getting the cartridge out?
