
lp-673 Rev. 000 Rel. 001 Date 8.30.18
42
Error Code
Error Code Description
Possible Remedies
Er:26
Outlet Water Temperature
(OP) Sensor Detects Water
Temperature Greater Than
219
o
F (104
o
C)
Press the Power button to clear the Error Code.
If Error happens again:
1. Ensure the pump is connected properly and operational. Replace pump if it is not operational.
2. Check Outlet temperature sensor. Ensure connections are secure.
3. Check Outlet sensor resistance. If resistance is zero, replace the sensor.
4. If the problem persists, replace the main control.
Er:28
Overheat Sensor (OH) Open
or Short
This Error Code will go away when temperature decreases.
If Error happens again:
1. Check overheat temperature sensor. Ensure connections are secure.
2. Check overheat sensor resistance. If resistance is zero, replace the sensor.
3. If the problem persists, replace the main control.
Er:29
APS - Closed is Normal, Open
is Fault
Press the Power button to clear the Error Code.
1. Check APS and main controller connections. Ensure all are secure.
2. Check APS resistance. If resistance is not zero, replace the switch.
3. Check APS hose. Ensure it is connected and in good condition.
4. Check condensate line and termination for blockages.
5. Check exhaust vent for blockages.
6. If the problem persists, replace the main control.
Er:30
Outlet Temperature Sensor
(ST) Fault
This Error Code will go away when outlet water temperature decreases.
If Error happens again:
1. Ensure the pump is connected properly and operational. Replace pump if it is not operational.
2. Check outlet temperature sensor. Ensure connections are secure.
3. Check outlet sensor resistance. If resistance is zero, replace the sensor.
4. If the problem persists, replace the main control.
Er:32
DHW Sensor (dH) Short
NOTE:
This error will only appear if an aquastat is installed and SEnS is selected in Installer Mode 39, or a
sensor is used and it is shorted.
This Error Code will go away if an aquastat is installed, AquA is selected in Installer Mode 39, and the water
heater is powered OFF and ON, or the DHW sensor is repaired or replaced.
1. Check DHW sensor. If an aquastat, ensure AquA is selected in Installer Mode 39. If a sensor, ensure
connections are secure.
2. Check DHW sensor resistance. If resistance is zero or does not match that in Table 38, replace the sensor.
3. After completing steps 1 and 2, power the water heater OFF. Then turn it back ON.
4. If the problem persists, replace the main control.
Er:33
H/X Temperature Sensor (OP)
Open or Short
This Error Code will go away when outlet water temperature decreases.
If Error happens again:
1. Check operating temperature sensor. Ensure connections are secure.
2. Check sensor resistance. If resistance is zero, replace the sensor.
3. If the problem persists, replace the main control.
Er:35
Exhaust Sensor (Eh) Open or
Short
This Error Code will go away when exhaust temperature decreases.
If Error happens again:
1. Check exhaust temperature sensor. Ensure connections are secure.
2. Check sensor resistance. If resistance is zero, replace the sensor.
3. Check exhaust vent for blockage.
4. If the problem persists, replace the main control.
Er:36
Abnormal Supply Voltage
Supply voltage is too low to operate. This Error Code will go away when supply voltage returns to normal
operating range.
If Error happens again:
1. Ensure water heater is properly wired to a power source meeting the requirements on the rating plate.
2. If problem persists, replace the main control.
Er:37
Abnormal Supply Frequency
Supply frequency is too high to operate. This Error Code will go away when supply frequency returns to
normal operating range.
If Error happens again:
1. Ensure water heater is properly wired to a power source meeting the requirements on the rating plate.
2. If problem persists, replace the main control.
Er:38
Error Appears When Control
Stores Data, but Data is not
Saved
Press the Power button to clear the Error Code.
Replace the main control.
Er:41
Fan Speed too high with
flame on
The Error Code will go away unless it occurs five (5) times in ten (10) minutes. Press the Power button to
clear the Error Code.
If Error happens again:
1. Check the vent connections for blockages.
2. Check the burner assembly.
3. Check fan operation. If fan appears to be operating normally but RPMs are too low or too high, replace
the fan.
4. If the problem persists, replace the main control.