THE THERMOSTATIC CARTRIDGE DOESN'T WORK PROPERLY

The first thing to do is to check if the hot and cold water pipes have been mounted in the correct way, not inverted. If from the tap you get only hot or cold water, surely the pipes have been inverted.

You must check that the pipes do not have any bendings or narrowings or dirt (such as residual bricks after works) which could obstruct the regular water flowing.

Check if the thermostatic tap and the filters are clean. See instructions.