We want to fit a thermostat shower unit. The hot and cold feed have been put in by our plumber but he is so busy we cannot get him back to complete. But we feel we could do this ourselves. Our question is - do we have to use any type of sealant on the metal threads before attaching the thermostat unit (also metal threads)? If so, what is best - ptfe or hemp come to mind, but as you can tell, our knowledge is scant. Hope someone can help. Thanks.
