Triangle Tube Boilers Error Codes

E01

Boiler will not fire, display shows E01 lockout

Ignition Failure Lockout

E02

Boiler shuts down with E02, no flame proven after ignition attempt

Flame Detection Failure

E03

Boiler locks out with E03, no ignition spark observed

Ignition Spark Circuit Failure

E04

Boiler displays E04 and will not start, fan may run briefly then stop

Air Pressure Switch / Combustion Air Fault

E05

Boiler shows E05, fan runs but burner does not light

Fan Speed / Combustion Blower Fault

E06

Boiler locks out with E06, temperature reading is erratic or out of range

Supply Temperature Sensor (NTC) Fault

E07

Boiler displays E07, return temperature reading is invalid

Return Temperature Sensor (NTC) Fault

E08

Boiler shows E08, domestic hot water (DHW) temperature reading is incorrect or missing

DHW Temperature Sensor Fault

E09

Boiler locks out with E09, high limit temperature exceeded

High Limit Overheat Trip

E10

Boiler shows E10, low water pressure or lack of water in system

Low Water Pressure / Low Water Cutoff

E11

Boiler displays E11, flue gas temperature too high

Flue Gas Overtemperature

E12

Boiler shows E12, communication error between display and main control

Control Board Communication Fault

E13

Boiler displays E13, outdoor temperature sensor reading is invalid

Outdoor Sensor Fault

E14

Boiler shows E14, domestic hot water flow is detected but burner does not modulate correctly

DHW Flow Sensor / Flow Switch Fault

E15

Boiler locks out with E15, condensate system fault detected

Condensate Drain Blockage

E16

Boiler shows E16, gas valve or gas train fault

Gas Valve Control Error

E17

Boiler displays E17, internal pump or primary circulator fault

Internal Circulator Pump Failure

E18

Boiler shows E18, flame present when there should be no flame

False Flame Detection

E19

Boiler displays E19, supply/return temperature difference too high

Delta-T Too High / Flow Insufficient

E20

Boiler shows E20, supply/return temperature difference too low

Delta-T Too Low / Excessive Flow or Sensor Error

Symptom

Boiler cabinet is very hot to the touch, insulation may smell or discolor

Overheating Cabinet / Insulation Issue

Symptom

Boiler cycles on and off rapidly when only a small zone is calling for heat

Micro-Zoning / Minimum Firing Rate Mismatch

Symptom

Boiler display is blank, no lights or response from controls

No Power to Boiler

Symptom

Boiler display is on but unresponsive, buttons do not change settings

User Interface / Keypad Failure

Symptom

Boiler emits a strong exhaust or burning smell near the unit

Combustion / Venting Odor Issue

Symptom

Boiler fan runs continuously even when there is no call for heat

Fan Stuck On / Post-Purge Control Issue

Symptom

Boiler frequently locks out during very cold weather but runs fine in mild temperatures

Cold Weather Performance / Intake or Condensate Issue

Symptom

Boiler frequently releases water from the pressure relief valve

Overpressure / Expansion Problem

Symptom

Boiler ignites with a loud boom or puff back

Delayed Ignition

Symptom

Boiler leaking water from bottom of cabinet

Internal Water Leak

Symptom

Boiler makes loud banging or knocking noises when starting or stopping

Kettling / Water Hammer in Hydronic System

Symptom

Boiler runs but house does not reach set temperature, radiators lukewarm

Insufficient Heat Output

Symptom

Boiler runs but makes a high-pitched whine from the fan area

Combustion Fan Bearing or Airflow Noise

Symptom

Boiler short cycles, turning on and off frequently without maintaining steady operation

Short Cycling / Control or Sizing Issue

Symptom

Domestic hot water temperature fluctuates, alternating between hot and cold

Inconsistent DHW Temperature

Symptom

No domestic hot water, but space heating works normally

DHW Priority / Diverter Fault

Symptom

No heat to radiators or underfloor loops, but boiler appears to run

No Space Heating Circulation