Hydronic Heat error codes

102 codes from 9 manufacturers, each with its meaning and the document it comes from. Open a code for the details, or search every system.

Alde Compact 3020/3030 HE (13)

• Low battery12V supply dropped below 10.8V (possible brownout); clears automatically at 11V (burner also shuts off below…
• Fan restartsIncorrect fan speed; a new start attempt is made (no action needed if it clears); repeated faults become 'Fan…
• Fan failureRepeated fan-speed faults after restarts
• Gas failureOut of gas or the gas is not igniting
• Overheat red failOverheat on the red cable - usually air in the system run at high power
• Overheat blue failOverheat on the blue cable
• Overheat PCBFailsafe in the heating system triggered (PCB overheat)
• Window openOptional window sensor triggered; gas heating is suspended (resumes when the window is closed)
• Heater not foundBreak in communication between the Alde control panel and boiler
• 3rd party C. failCommunication fault between Alde's panel and Alde Smart Control
• Panel failureMoisture trapped in the control panel
• Red connection failureProblem with the red cable or red contacts
• Yellow connection failProblem with the cable between the Alde panel and the CI-bus master panel or its connectors

Aqua-Hot (12)

• Ignition FailureReporter displays the verbatim fault 'Ignition Failure' -- the diesel burner attempted ignition but flame was…
• OVER-CURRENTA component (fan, pump, etc.) drew excessive current. Reporter has deactivated that output channel. Fault…
• OVER-TEMPERATURETank temperature exceeded the 215 degF high-limit trip (AHE-250 Service Manual: the high-limit thermostat…
• LOW VOLTAGEReporter supply voltage below 11.8V DC (Reporter operating range is 11-16V DC). Aqua-Hot still running but a…
• LOW LEVEL CUT-OFFBoiler fluid level below safety threshold. Reporter has shut down all fans/pumps/heat sources.
• SYSTEM VOLTAGESupply voltage out of range - the Reporter triggers a System Voltage fault when it receives below 11.8V DC…
• INDICATOR LIGHT GREENComponent active and operating normally
• INDICATOR LIGHT REDOn the Heating Zones / Pumps / Electric Element status lights specifically: electrical overload condition…
• DIESEL BURNER NO STARTDiesel burner fails to ignite after start sequence initiated
• NO HEAT OUTPUTNo heating output despite diesel burner or electric element operating
• LOW BATTERY VOLTAGEBattery voltage below minimum required for safe operation (typically <10.5 VDC)
• LOW TEMP CUTOFF ACTIVELow-Temperature Cutoff STATUS active (D4 indicator). Per the 200-Series Service Manual the LTCO status…

Aqua-Hot AHE-250-D03 (7)

• BURNER FAILED TO IGNITEDiesel burner attempted ignition but the photo-eye did not detect a sustained flame within the…
• OVERHEAT TRIPBoiler-coolant high-limit switch (215 deg F trip) opened, disabling the burner. The high-limit is…
• D1 LED OFFD1 is the Heating Status light (orange) on the relay control board - it illuminates ONLY when the burner…
• D4 LED NEVER ILLUMINATESOn the AHE-250 relay control board the indicator LEDs are D1 Heating Status (orange), D2 Electric Element…
• D5 LED OFF (OVERHEAT INDICATION)On the AHE-250 relay control board D5 = Burner Status (green) -- it illuminates when the burner switch is ON…
• COOLANT LEAK UNDER UNITPink/red boiler antifreeze visible below the Aqua-Hot cabinet. Loss of coolant will eventually trigger…
• SMOKE OR SOOT AT EXHAUSTVisible black smoke or accumulating soot at the exhaust pipe indicates incomplete combustion - downstream…

Aqua-Hot AHE-400-D02 (6)

• Ignition FailureReporter displays 'Ignition Failure' -- the Webasto WPX-909-180 diesel burner attempted ignition but no flame…
• AC ELEMENT NO HEATDiesel burner operating normally but the 120 V AC element does not contribute heat. AC element has failed…
• AC ELEMENT TRIPS PEDESTAL GFCIThe 120 V AC heating element has internal insulation failure (corrosion or moisture intrusion) that creates a…
• HEAT CALL USES DIESEL ON SHORE POWERCustomer reports the diesel burner runs even when the unit is connected to shore power and the AC element…
• WEBASTO BURNER PUMP PRESSURE LOWWebasto burner fuel-pump output pressure is below the burner's 145 PSI preset, causing poor atomization, weak…
• REPORTER DISPLAY BLANKOptional Aqua-Hot Reporter wall display is dark or unresponsive. Unit may still operate normally without the…

Aqua-Hot AHE-600-D04 (1)

• FUEL-CONSUMPTION-EXCEEDS-0.41-GPHAHE-600-D04 fuel consumption measured above 0.41 gal/hr nominal at full burn rate. Indicates over-firing …

Hurricane Heating System (9)

• 0Voltage Low or High - battery/supply voltage below 10.5 Vdc or about 15.5 Vdc. Burner shuts down, code 0…
• 1High Temperature - the high temperature limit has been reached. Burner shuts down, code 1, buzzer 10 s; board…
• 2Fuse - one of the fuses on the control board has blown. Burner shuts down, code 2, buzzer 10 s; board purges…
• 3Fuel Pump/Solenoid - the fuel pump or fuel solenoid has shorted. Burner shuts down, code 3, buzzer 10 s.
• 4Igniter - the igniter is open or shorted. Burner shuts down, code 4, buzzer 10 s.
• 5Combustion Fan - the combustion fan is open or shorted. Burner shuts down, code 5, buzzer 10 s.
• 6Circulating/Water Pump - the water pump is shorted. Burner shuts down, code 6, buzzer 10 s.
• 7Flameout - the flame went out or did not ignite. The board retries ignition two more times; after three…
• 8Compressor - the air compressor has shorted. Burner shuts down, code 8, buzzer 10 s.

Truma Combi (24)

• W 17 HSummer mode active with empty water container (boiler/DHW tank not filled). Heater pauses to prevent dry-fire…
• E 112 HCombustion failure - flame not detected / flame out (a problem with at least one of air, fuel, or spark). NOT…
• E 211 HCombustion failure - flame unstable during operation (catalogue 0211; air/fuel/spark combustion issue). NOT…
• E 212 HCombustion failure - gas supply interrupted / flame not detected (catalogue 0212). Ensure gas supply at…
• W 255 HCP Plus thermostat lost communication with Combi PCB
• E 122 HCombustion Failure: Flame not detected. Part of the 6-code combustion-failure family (E 112 H, E 121 H, E 122…
• 4 (PCB flash code ssss, slss)Current for combustion air motor too high. Combustion air motor, cable harness, or PCB fault.
• 5 (PCB flash code ssss, slsl)Current for combustion air motor too low. Combustion air motor, cable harness, or PCB fault.
• 6 (PCB flash code ssss, slls)Current for combustion air motor too high. Combustion air motor, cable harness, or PCB fault.
• 8 (PCB flash code ssss, lsss)Recheck flash code. Electronic fault - Failure in PCB.
• 10 (PCB flash code ssss, lsls)Plausibility of Combustion Air Sensor. Combustion Air Sensor outside of tolerance range - sensor or harness.
• W 18 HWarm air outlets blocked / circulated air intake blocked. Yellow indicator light flashes 9 times.
• 0020Plausibility of NTC Water Temperature Sensor. Water Temperature Sensor outside tolerance range …
• W 21 HPlausibility of NTC Room Temperature Sensor. Room Temperature Sensor outside tolerance range …
• W 22 HPlausibility of NTC Air Temperature Sensor. Air Temperature Sensor outside tolerance range - sensor/harness…
• E 24 HRisk of low voltage. Battery voltage too low < 10.4 V. (Published as warning 'W 24 H', not an 'E' fault; the…
• E 25 HCurrent for air circulation motor too low. Air circulation motor or PCB fault.
• E 26 HCurrent for air circulation motor too high. Air circulation motor or PCB fault.
• W 45 HNo 120VAC supply to Combi. Fault in 120VAC power supply, WECO manual reset switch engaged (Combi Plus only).
• E 69 HCurrent monitoring for air circulation motor with CP Plus - software error. Air circulation motor, CP Plus…
• E 121 HCombustion Failure: Flame unstable. Flame unstable during operation - potential combustion issue (air, fuel…
• E 148 HOvertemperature of the Combustion Air Temperature Sensor. Combustion Air Sensor outside tolerance range …
• E 149 HOvertemperature of the Water Temperature Switch or Air Temperature Switch. Water Temperature Switch or Air…
• E 150 HOvertemperature of the Air Temperature Switch or Water Temperature Switch. Air Temperature Switch or Water…

Truma Combi (older boards, 4-digit catalogue) (24)

• 0040Fault in the electronics
• 0041Electronics blocked: air or water temp switch opened from overheat OR combustion air sensor >215°C
• 0042Window switch detects open window OR PCB bridge for window switch interrupted
• 004312V power supply faulty (overvoltage)
• 004412V power supply faulty (low voltage)
• 0046Circulating air motor faulty OR control panel/cable faulty (or Combi E power selector switch)
• 0088Ignition spark interferes with electronics
• 0089Combustion air motor faulty
• 0094Heater overheats OR combustion air temp sensor incorrect value
• 0150Fault: air or water temp switch opened OR combustion air sensor >215°C
• 0090Fault in the electronics
• 0091Fault in the electronics
• 0092Fault in the electronics
• 0093Fault in the electronics
• 0160Fault in the electronics
• 0756Fault in the electronics
• 0800Fault in the electronics
• 0017Warning - water overheat condition.
• 0018Warning - air overheat condition.
• 0045230 V power supply faulty.
• 0112Combustion failure: flame out or not recognised; OR faulty power-supply earth connection.
• 0202Combustion failure: flame out or not recognised; OR faulty power-supply earth connection.
• 0211Flame unstable during operation.
• 0212Gas supply interrupted.

Truma Combi 4/6 E (older boards, pre-CP Plus) (6)

• 202Combi 4/6 E older boards: flame not detected (or poor earth/battery to minus terminal)
• 203Combi 4/6 E: flame not expected (ionization voltage in standby mode)
• 206Combi 4/6 E: dirty supply voltage (AC components in power supply)
• 208Combi 4/6 E: combustion engine RPM too low
• 209Combi 4/6 E: combustion engine RPM too high
• 210Combi 4/6 E: electronic fault on PCB