Abstract: The invention relates to an apparatus for cleaning an immersed surface, comprising a hollow body, guiding and driving members, a filtration chamber which is provided in the hollow body and which has at least one liquid inlet, at least one liquid outlet and a hydraulic circuit for circulation of liquid through a filtering device. An accelerometer device is fixedly joined to the hollow body and which is adapted to provide instantaneous measurements of at least one acceleration component of the terrestrial gravity in at least one fixed direction which is fixed relative to the hollow body, and a processing unit for processing the acceleration measurements supplied by the accelerometer device.

Abstract: Creating and utilizing electricity and radiation via actions of hoses is detailed. Likewise described is using electricity to heat the hoses and radiation to sanitize fluid such as water of a pool or spa. Electricity may be generated by pulsation of the hoses when employed together with a water-interruption type of automatic pool cleaner, for example. Hoses alternatively or additionally may include chemicals or materials reactive to light or other radiation.

Abstract: Disclosed is a heater including a back-flow preventing device located at or adjacent an outlet of the heater. In some embodiments, the back-flow preventing device has an open position and a closed position. When the back-flow preventing device is in the open position, water is able to flow freely through the heater. When back-flow preventing device is in the closed position, water is prevented from flowing or migrating back into the heater.

Abstract: Disclosed are systems and devices for controlling the amount of water passing through a heat exchanger and the amount of water that by-passes the heater without passing through the heat exchanger. In some embodiments, the system includes a by-pass valve assembly having means for sensing a time-varying characteristic of fluid adjacent the inlet, means for sensing a time-varying characteristic of fluid adjacent the outlet, and a valve that alters the amount of fluid by-passing the fluid heater in response to differences in the time-varying characteristic of fluid adjacent the inlet and fluid adjacent the outlet.