Rheem SVC 810, Troubleshooting Manual

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SVC 810 Tankless Troubleshooting Manual
7
Sequence of Operations
Action Explanation
Hot water faucet is open creating a demand Hot water draw initiates water flow thru
the machine.
Water flows through the Water Flow Sensor Minimum flow rate of .66 gallons per
minute.
Printed Circuit Board (PCB) senses the flow
rate has reached a minimum demand of 0.66
gpm PCB is the ‘brains’ of the machine and
controls all input and actions during
sequence of operations.
Fan conducts a pre-purge Pre purge is designed to verify we have a
clear and clean vent.
The Proportional Gas Flow Regulator allows
the gas to flow to the main burner PGFR opens to full BTU input initially.
At the same time, the igniter continuously
sparks and ignites the main burner The spark igniter ignites the fuel in the
main burner area. Both left and right
burner will fire initially.
After ignition, the Flame Rods sense and
monitor the flame and ensures combustion The purpose of the flame rods is to verify
flame. In the event of flame failure (or
presence when none is expect) the unit will
go into an error code.
The
“In Use Indicator”
on remote control
turns "ON" (Red) and the
Priority Indicator
turns Green (multiple remote controls).
Main Burner is now lit. The PCB goes thru
a series of calculations (input sensing) to
balance out the cold-water temperature, the
thermostat setting, the hot outlet
temperature and the BTU required to heat
the water.
The Proportional Gas Flow Regulator Valve
continuously adjusts the gas volume in order to
maintain the outlet temperature. The water
flow sensor also adjusts the proper amount of
cold water mix flow to supply a stable hot
water temperature at all times. A signal is also
sent to the fan motor in order to constantly
maintain the correct proportion between the
gas volume and air volume. Again, the PCB is constantly monitoring
all of these inputs and actions to ensure the
outlet water temperature is within 1 degree
of thermostat setting. It also monitors the
BTU required to heat the cold water to the
thermostat setting and adjusts the gas valve
accordingly.