Main Components

3. Thermal Fuse

The thermal fuse is an electric link which must be intact for the unit to operate. If the thermal fuse reaches a set temperature it will melt and the unit will shut down. The ther- mal fuse must be replaced if it melts. It is to protect against over heating and heat ex- changer splits where water may leak out and be super heated into steam.

4. Overheat Safety (Bi-metal Switch)

This Bi-metal Switch is fixed at the bend of the Heat Exchanger hot water outlet. If the temperature outlet from the heat exchanger reaches 950C the bi metal switch will open and the solenoid valve circuit is broken. This will cease combustion in case of overheat.

5. Combustion Fan

The combustion fan supplies primary air into the wing burners and secondary air up through the Bunsen style burners. The fan is DC low voltage and the speed is controlled by the PCB depending on the hot water supply and temperature. The fan speed is com- pared to the current required to attain that speed for air proving. If the fan current is over or under the parameters for the given speed the unit will shut down on air proving.

6. Water Volume Servo with Water Flow Sensor

6.1 Water Flow Sensor

Water flow sensing is done with a small turbine that spins when water travels through it in the correct direction. Each of the four fins on the turbine has a small magnet on it. Outside of the valve there is a magnetic sensor that detects the speed that the turbine is revolving. The revolution speed is input to the PCB which relates this speed to the water flow volume and determines whether it is sufficient for ignition.

6.2 Water Volume Flow Servo

The water volume is adjusted by opening and closing the water flow valve with the servo motor. This will limit the maximum hot water flow to 20 L/min, and will limit the water flow further when the burner is at high fire to ensure the temperature setpoint it met.

REU - 16 FUA - E specifications

The Rinnai REU-16 FUA-E is a cutting-edge tankless water heater designed for efficiency and convenience. This model is part of Rinnai's renowned line of high-performance appliances, catering to both residential and commercial applications. It boasts a sleek design coupled with advanced technology that sets it apart in the crowded water heating market.

One of the most notable features of the REU-16 FUA-E is its impressive heating capacity. It is capable of delivering hot water on demand, with a maximum output of 16 liters per minute. This means you can comfortably run multiple hot water fixtures simultaneously without experiencing a drop in temperature or flow rate. Whether you’re taking a shower, running the dishwasher, or washing clothes, this unit meets the demand with ease.

The REU-16 FUA-E employs a state-of-the-art condensing technology, which enhances its efficiency by capturing and reusing some of the heat that would otherwise escape through the flue. This allows for an energy efficiency rating of up to 95%, significantly reducing energy bills and environmental impact compared to traditional storage water heaters.

Another key characteristic of this unit is its compact size. The Rinnai REU-16 FUA-E can be installed in smaller spaces, making it an ideal option for apartments, houses, or commercial properties with limited room for bulky tank units. Its flexibility in installation positions—whether indoors or outdoors—provides additional versatility to users.

Safety is also a primary concern with the REU-16 FUA-E. It comes equipped with numerous safety features, including an anti-freezing function, overheat protection, and venting safety controls. These safeguards ensure safe operation for you and your family, providing peace of mind whether it’s running constantly or in standby mode.

In terms of controls, the Rinnai REU-16 FUA-E offers modern digital displays that provide real-time monitoring of water temperature and status. This user-friendly interface makes it easier for homeowners or users to adjust settings according to their preferences.

Overall, the Rinnai REU-16 FUA-E encapsulates innovation and efficiency in water heating. Its combination of advanced technology, high performance, compact design, and safety features makes it a reliable choice for those seeking a consistent supply of hot water without the limitations of traditional systems. Whether for residential use or commercial applications, the REU-16 FUA-E is engineered to provide lasting performance and convenience.