Operation Principles - Rinnai REU-V2632FFUG Service Manual

8. Operation Principles

Hot Water Operation
1. Ignition
• Activate water controllers (if fitted) and open the hot water tap (for full details regarding operation of
controllers refer to the 'Customer Operation/Installation manual' supplied with water heater).
• When water flows through the unit, the water flow sensor rotates and sends an electrical 'pulse' signal
to the Printed Circuit Board (PCB). This signal is proportional to the water flow rate.
• The PCB sends electrical current to the combustion fan motor causing it to turn. The fan motor sends
an electrical pulse signal to the PCB. If fan rotation is OK, the main solenoid and changeover solenoid
valves open as required, the spark generator activates and the spark electrode ignites the burner.
2. Water Temperature and Flow
• The PCB will automatically control operation of th e internal components to achieve the programmed
temperature. When a high tempe rature rise is required, the PCB may cause the Water Flow Servo to
close partially resulting in a lowe r flow ra te to ac hieve th e p rogrammed tempera ture. This is a
necessary operational feature of the unit.
• When operating in 'Bath Fill' mode , the signal from the water flow sen sor is also used by the PCB to
compute the volume of water tha t has been passed through the unit at any insta nt whilst the ba th is
filling.
3. Shut Down
• When operating in 'Bath F ill' mode, the PCB causes the Water F low Serv o to close when the
programmed Bath Fill volume has pas sed through the unit. Alternatively, flow is stopped when the
user closes the hot water tap.
• When water flow stops, the water flow sensor stops rotating and the pulse signal to the PCB stops. The
PCB then causes the main solenoid and solenoid valves to close an d the burner is extinguished. The
combustion fan will continue to operate for some time to purge the combustion chamber.
Infinity REU-V2632FFUG / HD200i REU-VM2632FFUC - 11 - Issue 1 - 16/12/09 ©Rinnai