Paloma PH-28RIFSN, Engineering Handbook

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2. Error Code [32] (Heat Exchanger Thermistor Disconnection) is displayed.
Display maintenance information [4y].
[4y] indicates the temperature detected by the heat exchanger thermistor.
Does
[4y] indicate the hot
water outlet
temperature?
NO
YES
The water heater seems to be
normal. Try to operate again.
Is the
resistance of the
heat exchanger
thermistor OK?
*2
NO
YES
Replace Burner Control Assy.
Replace Heat Exchanger
Thermistor.
3. Error Code [33] (Hot Water Outlet Thermistor Disconnection) is displayed.
Display maintenance information [5y].
[5y] indicates the temperature detected by the hot water outlet thermistor.
Does
[5y] indicate the hot
water outlet
temperature?
NO
YES
The water heater seems to be
normal. Try to operate again.
Is the
resistance of the
hot water outlet
thermistor OK?
*3
NO
YES
Replace Burner Control Assy.
Replace Hot Water Outlet
Thermistor.
4. Error Code [34] (Ambient Air Thermistor Disconnection, Short Circuit) is displayed.
Display maintenance information [2y].
[2y] indicates the temperature detected by the ambient air thermistor.
Does
[2y] indicate the
ambient air
temperature?
NO
YES
The water heater seems to be
normal. Try to operate again.
Is the
resistance of the
ambient air
thermistor OK?
*4
NO
YES
Replace Burner Control Assy.
Replace Ambient Air
Thermistor.
*2 Measure the resistance of connector .
Between Yellow and Black wires:
R
68
104 °F (20 °C) ........ 10.3 k ohm
°F (40 °C) ........ 4.9 k ohm
*3 Measure the resistance of connector .
Between Red and Black wires:
R
68
104 °F (20 °C) ........ 10.3 k ohm
°F (40 °C) ........ 4.9 k ohm
*4 Measure the resistance of connector .
Between Blue and Black wires:
R
68
104 °F (20 °C) ........ 10.3 k ohm
°F (40 °C) ........ 4.9 k ohm