Installation Manual

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Problem solving
8 Problem solving
8.1 Error code diagnostics
i
To remove error code from the
display, press the reset button.
Display Cause Solution
Fault in the flue gas limiter.
Temperature above 230°F
(110°C) inside the cabinet.
1. Check continuity of the flue gas limiter (see Fig. 73 , page 54 ).
Go to steps two and three to determine air box temperature
sensor fault and replace it.
2. Check for flue gas leakage around the top and bottom seals of
heat exchanger use mirror to check around the rear as well as the
viewing window.
3. Check that flue gas limiter connector and spade connections
are secure.
4. Unplug heater and check the wiring harness connections inside
the control board.
Appliance selection on “P7” mode
is not correct.
1. Check “P7” mode: the water heater requires setting “NC”.
2. Check jumper and connection on sensor at upper right hand
corner of heat exchanger.
3. Measure jumper resistance, must be 115-125 ohms.
Backflow temperature sensor
defect - happens if sensor is
disconnected or short circuit.
1. Check blackflow temperature sensor connection. See Fig. 73 ,
page 54 .
2. Replace backflow temperature sensor.
3. Check sensor (ref. page 52 , chapter 10 ).
Outlet temperature sensor fault
(Temperature below 36°F or above
210°F).
1. Check red wire connections at hot water temperature sensor.
Clean terminals with an eraser. If badly corroded, replace sensor
and wire harness. See Fig. 73 , page 54.
2. Sensor may trip if water temperature drops below 36°F to
protect heater from freezing conditions. Any damage due to
freezing conditions is not covered under warranty.
3. In areas where water has a high mineral content, periodic
descaling may be necessary.
4. Check sensor (ref. page 51 , chapter 10 ).
Table 30
* By installer or service technician only.