The present invention discloses a reliable and stable water heater mechanism. The mechanism comprises a pedestal body (1) embedded into a wall body, a receiving cavity (6) is disposed inside a right side of the pedestal body (1) and is internally provided with a water heater installation and connection component (2), a connector (21) with a fastening slot (22) is disposed on the water heater installation and connection component (2), an operating cavity (3) is disposed in the upper part inside a left side wall of the pedestal body (1) while a locking groove (4) is disposed in the lower part inside the left side wall of the pedestal body (1), the operating cavity (3) is internally provided with a first outer teeth drive wheel (51) and a second outer teeth drive wheel (92), a rotating rod (5) is fixedly arranged on the first outer teeth drive wheel (51), the top part of the rotating rod (5) is connected in a rotating manner with the inner wall of the pedestal body (1), the bottom part of the rotating rod (5) extends downwards along the left side inner wall of the pedestal body (1), and a first bevel wheel (91) is fixedly disposed at the top part of the second outer teeth drive wheel (92). The reliable and stable water heater mechanism provided by the invention is simple in structure, convenient in installation and high in practicability and security, and the maintaining speed is raised.