Which trade is authorized to maintain thermostatic mixing valves in Au Home › Forums › Public Forums › General Plumbing › Which trade is authorized to maintain thermostatic mixing valves in Au This topic has 1 reply, 2 voices, and was last updated 23 years, 9 months ago by Robert Stephen Morton. Viewing 1 reply thread Author Posts 3 Apr 2001 at 10:48 pm #274841 MasterPlumbersKeymaster Which trade is authorized to maintain thermostatic mixing valves in Australia? 4 Apr 2001 at 7:15 am #290593 Robert Stephen MortonParticipant Licensed Plumbers! In Qld there is a course to be certified. However the course is not available in some areas just yet. Author Posts Viewing 1 reply thread You must be logged in to reply to this topic. Log In Username: Password: Keep me signed in Log In