119
Operating the Boiler
11.14 Understanding Error Codes
When an error code appears on the front panel, refer to the following chart for a definition and possible remedy
for the situation.
Error Code Reason
Self-diagnostic/Action
E001
Heat Exchanger Overheat
Check for proper system flow.
E003
Ignition Failure
Check gas supply valve and igniter.
E004
False Flame
Check electric ground.
E012
Flame Loss
Check gas, venting and condensate trap.
E016
Heat Exchanger Overheat
Check flow, clean system filters.
E030
Exhaust Overheat
Check flow, clean system filters.
E046
Heat Exchanger Thermistor
Check thermistor connector.
E047
Exhaust Thermistor
Check thermistor connector.
E060
Abnormal Dual Venturi
Check dual venturi.
E109
Abnormal Fan Motor
Check fan and venting.
E110
Exhaust Blockage
Check exhaust venting.
E205
Heating Supply Temp.Sensor
Check flow, thermistor connector.
E218
Heating Return Temp.Sensor
Check thermistor connector.
E278
Ext. Supply Sensor Not Detected
Check sensor connections.
E279
Ext. Return Sensor Not Detected
Check sensor connections.
E291
Return Temp. Exceeds Supply
Check for reversed piping.
E302
Low Water Pressure
Check water pressure.
E352
High Water Pressure
Check water pressure.
E353
Water Pressure Sensor
Check WPS.
E480
DHW Tank Sensor Not Detected
Check sensor connections.
E515
Abnormal PCB
Check PCB connections.
E517
Abnormal DIP Switch
Check DIP switch settings.
E594
Abnormal EEPROM
Check the PCB.
E615
Abnormal Memory
Check PCB connections.
E736
Cascade Communication
Check cascade cable.
E740
Outdoor Sensor Not Detected
Check sensor connections.
E762
Vent Pipe Not Fully Inserted
Insert pipe 2-3/4“ (70 mm) into exhaust collar.
E777
Low Water Cutoff Activated
Check supply water.
E782
Front Panel Communication
Check panel connections.
E784
Zone Controller Communication
Check wiring and settings.
E786
Improper Front Panel Detected
Check for correct panel version.
E788
Incorrect Gas Type Setting
Check DIP switch setting.
If any of these remedies do not resolve the problem, contact Technical Support at 1-800-519-8794.
