Sequence Of Operations - Dometic G6A-8E Service Manual

Water Heater

4.5 Sequence of Operations

Understanding the sequence of operations for a Water
Heater is an important part of diagnosing the operational
issues occurring in the Water Heater. This section details
the sequence of operation for each Water Heater type.
Gas/Electric Combination Models
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Gas/Electric Combination Water Heater Operation Flow
1–5 = Electric Sequence of Operations
6–9 = Gas Sequence of Operations
Electric Sequence of Operation for Gas/
Electric Combination Models
1. With the wall switch turned On for electric, 12 VDC
power is sent out of the switch and into the white
wire on the wire harness and into the control board.
2. DC voltage leaves the control board on the top
brown wire, passes through the thermostat and the
thermal cut-off, and travels back into the control
board on the bottom brown wire.
3. DC voltage leaves the control board on the yellow
wire to the relay on the back of the Water Heater.
4. DC voltage closes the relay with an audible click.
5. AC voltage travels on the black wire from the relay to
the heating element.
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Gas Sequence of Operation for Gas/Electric
Combination Models
6. With the wall switch turned On for gas, 12 VDC power
is sent out of the switch and into the orange wire on
the wire harness and into the control board.
7. DC voltage leaves the control board on the top
brown wire, passes through the thermostat and the
thermal cut-off, and travels back into the control
board on the bottom brown wire.
8. DC voltage leaves the control board on the red wire,
moves through the E.C.O., and opens the valves to
allow gas to flow through the gas solenoid valve.
9. Voltage leaves the ignitor circuit on the control
board to create a spark. The ignitor attempts to light
for seven seconds.
a. If the unit lights, the electrode heats up and sends
a ground signal to the control board. The ignitor
stops sparking and the valves stay open during
the heating process.
b. If the unit fails to ignite, there is an approximate
10-second delay before the next attempt.
c. After three failed ignition attempts, the Water
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Heater goes into lockout mode.
Gas Only Models
7 Gas Only Water Heater Operation Flow
General Information
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