If you need to install a gas appliance, always contact a licensed gasfitter or gas plumbers to do it for you. These types of projects require a level of expertise that only trained professional plumbers have. It’s both dangerous and illegal to try your hand at installing gas appliances yourself. NSW government legal provisions clearly specify that only certified gasfitters or gas plumbers are allowed to handle gas work, be it installing hot water units or gas cooktops, in order to ensure consumer safety.