IBC Technologies · Error codes
IBC Technologies error codes and alerts
Identical code numbers can mean different things on different controllers, so every entry is tied to the documented series, controller and manual version. A code is never a diagnosis.
If you smell gas
- Stop what you are doing. Do not use phones, switches, matches or anything that can spark inside.
- Go outside and leave the door open behind you.
- Call the FortisBC 24-hour emergency line at 1-800-663-9911 or dial 911.
Only after that, call ROMA about the boiler. Official guidance: FortisBC gas leaks and odour.
IBC SL Series G3 residential boilers with the V-10 touchscreen controller
Error – Ignition trials exceeded
IBC's installation and operating manual lists this alert when the boiler fails to light on three successive ignition attempts. The control t…
Lockout
Error – Water High-Limit
The manual lists this alert when the boiler water temperature exceeds the high-limit threshold (208°F, or 201°F sustained for 15 seconds). T…
Lockout
Error – Low Water Cutoff
The manual lists this alert when the boiler's safety and ignition module detects a low-water condition inside the boiler. The boiler locks o…
Lockout
Error: Interlock [1 or 2] Open
The manual lists this alert when an interlock circuit wired to the boiler's low-voltage terminals is open. That is either the factory jumper…
Lockout
Error: Vent High Limit
The manual lists this alert when the exhaust (flue) gas temperature exceeds the venting material's limit — 248°F for six seconds or 232°F fo…
Lockout
Error – Max. delta T Exceeded
The manual lists this alert when the outlet water temperature is more than 45°F above the inlet (return) temperature, or when the outlet tem…
Details
Error – Low RPM / Air Flow
The manual lists this alert when the combustion fan is below 1,150 RPM at the end of fan pre-purge, or below 100 RPM during heating. The con…
Details
Error – Fan Pressure
The manual lists this alert when the fan power consumed by the safety and ignition module (SIM+) exceeds its threshold during operation. It …
Details
Error – Module High Current
The manual lists this alert when the voltage supply to the safety and ignition module (SIM+) and gas valve exceeds 24 VAC. The module monito…
Details
Error – Low Module Current
The manual lists this alert when the current drawn by the gas valve circuit stays below its expected range (starting below 25 mA or staying …
Details
Error – Low Water Pressure
The manual lists this alert when the boiler's inlet water pressure reads below 4 psi. A sealed hydronic system needs enough pressure to keep…
Details
Error – Inlet Pres. Sensor
The manual lists this alert when the inlet water-pressure sensor appears shorted or disconnected. The control can no longer trust its water-…
Details
Error – See: Status > SIM menu > Status
The manual lists this message when the safety and ignition module (SIM+) has detected an error that subsequently cleared on its own. The dis…
Details
Error – Roll Out Switch
The manual lists this alert when the rollout switch beside the combustion chamber detects 230°F, meaning flame or hot combustion gas is roll…
Safety
Error – Controller Board
The manual lists this alert when the control board detects an internal error. Poor incoming power is the typical cause noted in the manual, …
Details
Error – No Boilernet Comm
The manual lists this alert when a boiler configured as the Master in a network (cascade) cannot detect at least one other boiler board on t…
Details
Error – No MAC address
The manual lists this alert when a boiler on a Boilernet network cannot verify a valid MAC address for its network interface. Without a vali…
Details
Error – Flame Signal / Vent Block
The manual lists this alert when the flame current measured by the SIM+ module drops below the minimum for the model. A weak flame signal ca…
Details
Error – Reversed Flow
The manual lists this alert when the return (inlet) temperature reads higher than the supply (outlet) temperature for ten minutes. The boile…
Details
Error – Temp. probe error
The manual lists this alert when an internal temperature sensor appears shorted or open-circuit, or when paired (dual) sensors deliver diver…
Details
Error – Unhandled error code
The manual reserves this alert for unforeseen conditions the controller software does not have a specific message for. The guidance is to co…
Details
Outlet Limited
The manual lists this warning when the controller detects a difference greater than 40°F between the inlet and outlet temperature sensors. T…
Details
Remote offline
The manual lists this warning when a boiler configured as the Master in a network cannot detect any subordinate boilers. It appears on netwo…
Details
Unoccupied
The manual lists this warning when the Occupied box in the controller's User Menu has been unchecked. The boiler is telling you it will not …
Details
Summer
The manual lists this warning when a thermostat call for space heating arrives but the outdoor temperature is above the Summer Shutdown temp…
Details
Failsafe Setpoint
The manual lists this warning when a subordinate boiler in a network has lost contact with its Master, or a boiler set up for external contr…
Details
IBC VX Series boilers with the V-10 touchscreen controller
Error – Ignition trials exceeded
IBC's manual lists this alert when the boiler fails to light on three successive ignition attempts. The control then enters a one-hour locko…
Lockout
Error – Water High-Limit
The manual lists this alert when the boiler water temperature exceeds the high-limit threshold (208°F, or 201°F sustained for 15 seconds). T…
Lockout
Error – Low Water Cutoff
The manual lists this alert when the boiler's safety and ignition module detects a low-water condition inside the boiler. The boiler locks o…
Lockout
Error: Interlock [1 or 2] Open
The manual lists this alert when an interlock circuit wired to the boiler's low-voltage terminals is open. That is either the factory jumper…
Lockout
Error: Vent High Limit
The manual lists this alert when the exhaust (flue) gas temperature exceeds the venting material's limit — 248°F for six seconds or 232°F fo…
Lockout
Error – Max. delta T Exceeded
The manual lists this alert when the outlet water temperature is more than 45°F above the inlet (return) temperature, or when the outlet tem…
Details
Error – Low RPM / Air Flow
The manual lists this alert when the combustion fan is below 1,150 RPM at the end of fan pre-purge, or below 100 RPM during heating. The con…
Details
Error – Fan Pressure
The manual lists this alert when the fan power consumed by the safety and ignition module (SIM+) exceeds its threshold during operation. It …
Details
Error – Module High Current
The manual lists this alert when the voltage supply to the safety and ignition module (SIM+) and gas valve exceeds 24 VAC. The module monito…
Details
Error – Low Module Current
The manual lists this alert when the current drawn by the gas valve circuit stays below its expected range (starting below 25 mA or staying …
Details
Error – Low Water Pressure
The manual lists this alert when the boiler's inlet water pressure reads below 4 psi. A sealed hydronic system needs enough pressure to keep…
Details
Error – Inlet Pres. Sensor
The manual lists this alert when the inlet water-pressure sensor appears shorted or disconnected. The control can no longer trust its water-…
Details
Error – See: Status > SIM menu > Status
The manual lists this message when the safety and ignition module (SIM+) has detected an error that subsequently cleared on its own. The dis…
Details
Error – Roll Out Switch
The manual lists this alert when the rollout switch beside the combustion chamber detects 230°F, meaning flame or hot combustion gas is roll…
Safety
Error – Controller Board
The manual lists this alert when the control board detects an internal error. Poor incoming power is the typical cause noted in the manual, …
Details
Error – No Boilernet Comm
The manual lists this alert when a boiler configured as the Master in a network (cascade) cannot detect at least one other boiler board on t…
Details
Error – No MAC address
The manual lists this alert when a boiler on a Boilernet network cannot verify a valid MAC address for its network interface. Without a vali…
Details
Error – Flame Signal / Vent Block
The manual lists this alert when the flame current measured by the SIM+ module drops below the minimum for the model. A weak flame signal ca…
Details
Error – Reversed Flow
The manual lists this alert when the return (inlet) temperature reads higher than the supply (outlet) temperature for ten minutes. The boile…
Details
Error – Temp. probe error
The manual lists this alert when an internal temperature sensor appears shorted or open-circuit, or when paired (dual) sensors deliver diver…
Details
Error – Unhandled error code
The manual reserves this alert for unforeseen conditions the controller software does not have a specific message for. The guidance is to co…
Details
Outlet Limited
The manual lists this warning when the controller detects a difference greater than 40°F between the inlet and outlet temperature sensors. T…
Details
Remote offline
The manual lists this warning when a boiler configured as the Master in a network cannot detect any subordinate boilers. It appears on netwo…
Details
Unoccupied
The manual lists this warning when the Occupied box in the controller's User Menu has been unchecked. The boiler is telling you it will not …
Details
Summer
The manual lists this warning when a thermostat call for space heating arrives but the outdoor temperature is above the Summer Shutdown temp…
Details
Failsafe Setpoint
The manual lists this warning when a subordinate boiler in a network has lost contact with its Master, or a boiler set up for external contr…
Details
IBC Superflow SFC-1 combi boilers with the numeric-display control
F000
The controller has detected a fault in the heat exchanger temperature sensor circuit. The sensor's reading is no longer trusted, so the cont…
Details
F001
The controller detected the heat exchanger temperature rising too high while the combi was heating the central-heating circuit. The unit sto…
Lockout
F002
The controller detected the heat exchanger temperature rising too high while the appliance was producing domestic hot water. The unit stops …
Lockout
F003
The controller detected the flue (exhaust) temperature above its safe limit. Flue temperature climbs when the heat exchanger is not absorbin…
Lockout
F004
The controller made four ignition trials and detected no flame in any of them, so the unit locked out. The manual's checks span the gas supp…
Lockout
F005
The appliance was firing and the controller then lost the flame signal during operation. The unit stops rather than continue without a prove…
Lockout
F006
The controller detected a flame signal at a moment when the burner should be off. A stray flame signal can indicate a gas valve passing gas …
Safety
F007
The controller measures the flame signal as weaker than expected. A weak signal can make the appliance unreliable at proving the flame, even…
Details
F008
The controller measured the combustion fan at a speed outside what it expects for the operating state. Fan speed is how the appliance contro…
Details
F009
The control module has detected an internal fault. The manual's approach is to remove field wiring and reset to see whether the fault was ca…
Lockout
F010
The heat exchanger temperature sensor reads as an open circuit. The controller cannot measure heat exchanger temperature and flags the circu…
Details
F011
The heat exchanger temperature sensor reads as a short circuit. The controller flags the sensor circuit rather than trusting an implausible …
Details
F012
The flue (exhaust) temperature sensor reads as an open circuit. Without a flue temperature reading the controller cannot apply its flue over…
Details
F013
The domestic hot-water inlet temperature sensor reads as open or shorted. The controller uses that sensor to manage hot-water output tempera…
Details
F014
The heat exchanger temperature is not changing while the unit is fired, which tells the controller the sensor may not be properly mounted on…
Details
F015
The controller measured the temperature inside the appliance cabinet above its limit. The manual's checks point to flue gas leaking from the…
Details
F016
The DHW outlet temperature is not changing while the unit is fired, which tells the controller the DHW outlet sensor may not be mounted corr…
Details
F017
The controller detected a fault in the DHW bypass valve circuit. The bypass valve steadies hot-water temperature when draws start and stop.…
Details
F018
The controller has detected a restriction in the flue or combustion-air path. The unit stops rather than risk running with inadequate combus…
Lockout
F019
The controller cannot communicate properly with the Boiler Memory Module (BMM), which stores the unit's configuration. Without it the contro…
Details
F021
The controller detected that a critical setup parameter was changed in a way it does not accept, and it is asking for a factory reset of the…
Details
F027
The outdoor temperature sensor connected to the combi reads as shorted. The controller uses outdoor temperature for weather-based control.…
Details
F028
The controller detects the reset (wrench) button being activated unintentionally — for example pressed continuously by something leaning on …
Details
F029
The controller detected a fault in the gas valve circuit. Because the gas valve controls fuel flow into the burner, the unit locks out until…
Lockout
F031
The central-heating supply temperature sensor reads as open or shorted. The controller uses supply temperature to manage heating output.…
Details
F040
A cabinet (internal air) temperature sensor reads as an open circuit. The controller monitors cabinet temperature for overheating conditions…
Details
F041
A cabinet temperature sensor reads as shorted. The controller cannot trust its cabinet temperature reading.…
Details
F042
In a cascade installation, the controller reports that cascade domestic hot water is not available, usually because another lockout in the c…
Details
--
The controller shows two blinking dashes (--) when the water pressure sensor circuit is faulty. Without a trustworthy pressure reading the c…
Lockout
E
The display shows a flashing E for a control module internal error that disables operation entirely. The manual's approach is to remove fiel…
Lockout
n030
A notification that the DHW outlet temperature sensor reads as open or shorted. Unlike a fault, a notification usually appears without stopp…
Details
n040
A notification that a unit in a cascade has lost communication with its Leader. The cascade cannot coordinate firing while the link is down.…
Details
n041
A notification that the cascade system temperature sensor wired to the Leader reads as open. The cascade uses the system sensor to manage th…
Details
n120
The controller is recommending maintenance based on hours of use. The unit continues to operate normally.…
Details
n121
Maintenance is now required based on hours of use, and the controller has limited domestic hot-water output until it is performed. Heating m…
Details
n122
Maintenance is required based on hours of use and the controller has disabled domestic hot-water output until it is performed. Heating may c…
Details
n150
The controller detected a high heat exchanger temperature and is limiting burner output to protect the heat exchanger, rather than shutting …
Details
n151
The controller detected a high flue temperature and is limiting burner output to protect the venting, rather than shutting the unit down.…
Details
n152
The flue temperature is not changing while the unit is fired, which tells the controller the flue sensor may not be properly mounted on the …
Details
n201
The controller has activated the heat exchanger air-purge routine, which happens when air is trapped in the heat exchanger, an isolation val…
Details
n202
The controller detected a high flue temperature and has disabled the burner to protect the venting. This is a step short of a full lockout b…
Details
n245
The controller detected flue gas flowing back through the unit while the fan runs at low speed. The manual's checks cover the vent and combu…
Details
IBC Superflow SFT-1 tankless water heater with the numeric-display control
F000
The controller has detected a fault in the heat exchanger temperature sensor circuit. The sensor's reading is no longer trusted, so the cont…
Details
F002
The controller detected the heat exchanger temperature rising too high while the appliance was producing domestic hot water. The unit stops …
Lockout
F003
The controller detected the flue (exhaust) temperature above its safe limit. Flue temperature climbs when the heat exchanger is not absorbin…
Lockout
F004
The controller made four ignition trials and detected no flame in any of them, so the unit locked out. The manual's checks span the gas supp…
Lockout
F005
The appliance was firing and the controller then lost the flame signal during operation. The unit stops rather than continue without a prove…
Lockout
F006
The controller detected a flame signal at a moment when the burner should be off. A stray flame signal can indicate a gas valve passing gas …
Safety
F007
The controller measures the flame signal as weaker than expected. A weak signal can make the appliance unreliable at proving the flame, even…
Details
F008
The controller measured the combustion fan at a speed outside what it expects for the operating state. Fan speed is how the appliance contro…
Details
F009
The control module has detected an internal fault. The manual's approach is to remove field wiring and reset to see whether the fault was ca…
Lockout
F010
The heat exchanger temperature sensor reads as an open circuit. The controller cannot measure heat exchanger temperature and flags the circu…
Details
F011
The heat exchanger temperature sensor reads as a short circuit. The controller flags the sensor circuit rather than trusting an implausible …
Details
F012
The flue (exhaust) temperature sensor reads as an open circuit. Without a flue temperature reading the controller cannot apply its flue over…
Details
F013
The domestic hot-water inlet temperature sensor reads as open or shorted. The controller uses that sensor to manage hot-water output tempera…
Details
F014
The heat exchanger temperature is not changing while the unit is fired, which tells the controller the sensor may not be properly mounted on…
Details
F015
The controller measured the temperature inside the appliance cabinet above its limit. The manual's checks point to flue gas leaking from the…
Details
F016
The DHW outlet temperature is not changing while the unit is fired, which tells the controller the DHW outlet sensor may not be mounted corr…
Details
F017
The controller detected a fault in the DHW bypass valve circuit. The bypass valve steadies hot-water temperature when draws start and stop.…
Details
F018
The controller has detected a restriction in the flue or combustion-air path. The unit stops rather than risk running with inadequate combus…
Lockout
F019
The controller cannot communicate properly with the Boiler Memory Module (BMM), which stores the unit's configuration. Without it the contro…
Details
F021
The controller detected that a critical setup parameter was changed in a way it does not accept, and it is asking for a factory reset of the…
Details
F028
The controller detects the reset (wrench) button being activated unintentionally — for example pressed continuously by something leaning on …
Details
F029
The controller detected a fault in the gas valve circuit. Because the gas valve controls fuel flow into the burner, the unit locks out until…
Lockout
F040
A cabinet (internal air) temperature sensor reads as an open circuit. The controller monitors cabinet temperature for overheating conditions…
Details
F041
A cabinet temperature sensor reads as shorted. The controller cannot trust its cabinet temperature reading.…
Details
F042
In a cascade installation, the controller reports that cascade domestic hot water is not available, usually because another lockout in the c…
Details
--
The controller shows two blinking dashes (--) when the water pressure sensor circuit is faulty. Without a trustworthy pressure reading the c…
Lockout
E
The display shows a flashing E for a control module internal error that disables operation entirely. The manual's approach is to remove fiel…
Lockout
n030
A notification that the DHW outlet temperature sensor reads as open or shorted. Unlike a fault, a notification usually appears without stopp…
Details
n040
A notification that a unit in a cascade has lost communication with its Leader. The cascade cannot coordinate firing while the link is down.…
Details
n041
A notification that the cascade system temperature sensor wired to the Leader reads as open. The cascade uses the system sensor to manage th…
Details
n120
The controller is recommending maintenance based on hours of use. The unit continues to operate normally.…
Details
n121
Maintenance is now required based on hours of use, and the controller has limited domestic hot-water output until it is performed. Heating m…
Details
n122
Maintenance is required based on hours of use and the controller has disabled domestic hot-water output until it is performed. Heating may c…
Details
n150
The controller detected a high heat exchanger temperature and is limiting burner output to protect the heat exchanger, rather than shutting …
Details
n151
The controller detected a high flue temperature and is limiting burner output to protect the venting, rather than shutting the unit down.…
Details
n152
The flue temperature is not changing while the unit is fired, which tells the controller the flue sensor may not be properly mounted on the …
Details
n201
The controller has activated the heat exchanger air-purge routine, which happens when air is trapped in the heat exchanger, an isolation val…
Details
n202
The controller detected a high flue temperature and has disabled the burner to protect the venting. This is a step short of a full lockout b…
Details
n245
The controller detected flue gas flowing back through the unit while the fan runs at low speed. The manual's checks cover the vent and combu…
Details
IBC SL G3 light-commercial boilers (V-10 controller, manual 120-270E12)
Ignition Trials Exceeded
Ignition trials exceeded error. Ignition failure after 3 tries; boiler has failed to ignite on 3 successive attempts. Boiler is in lockout f…
Lockout
Water High Limit
Water High Limit error. Water temperature exceeds 208°F, or 201°F for 15 sec. Boiler is in hard lockout mode. The table classifies it as ala…
Lockout
Low Water Cutoff
Low Water Cut-off error. The Safety and Ignition module has detected a low water condition. The table classifies it as alarm.…
Lockout
Interlock 1 or 2 Open
Interlock 1 or 2 error. Jumper lead on Interlock terminals of TB2 is loose or compromised; or external safety is in an alarm state. The tabl…
Details
Vent High Limit
Vent High Limit. Exhaust gas temperature exceeds 248°F for 6 seconds, or 232°F for 60 sec. Boiler is in hard lockout mode. The table classif…
Lockout
Max. delta T Exceeded
Max. delta T Exceeded. Outlet is more than 45°F (25°C) above the inlet temperature; outlet is rising faster than 9°F (5°C) per minute. The t…
Details
Low RPM / Air Flow
Low RPM / Air Flow. Fan is below 1150 RPM at the end of fan pre-purge, or below 100 RPM during heating. The table classifies it as alarm.…
Details
Module High Current
Module High Current. Exceeded 24 VAC to SIM and gas valve. The table classifies it as alarm.…
Details
Low Module Current
Low Module Current. Inadequate current to gas valve (starts below 25mA or stays below 20mA). The table classifies it as alarm.…
Details
Low Water Pressure
Low Water Pressure. Inlet water pressure below 4 psi. The table classifies it as alarm.…
Details
Inlet Pres. Sensor
Inlet Pres. Sensor. Inlet water pressure sensor appears to be shorted or disconnected. The table classifies it as alarm.…
Details
See: Status > SIM menu > Status
See: Status > SIM menu > Status. SIM has detected an error that has subsequently cleared. The table classifies it as alarm.…
Details
Roll Out Switch
Roll Out Switch. Rollout switch, by combustion chamber, has detected 230°F temperature. The table classifies it as alarm.…
Details
Controller Board
Controller Board. Error internal to control board; typically result of poor incoming power; may require a reboot. The table classifies it as…
Details
No Boilernet Comm
No Boilernet Comm. Controller set as Master detects a CANbus wiring issue. The table classifies it as alarm.…
Details
No MAC address
No MAC address. Boiler cannot verify a valid MAC address. The table classifies it as alarm.…
Details
[Vent High Pressure]
[Vent High Pressure] (manual prints "Erreur - [Vent High Pressure]"). Pressure switch has opened while the boiler is in pre-purge or heating…
Details
Flame Signal / Vent Block
Flame Signal / Vent Block. SIM flame current drops below minimum values: SL 26-260 G3 1.8 μA, SL 40-399 G3 2.0 μA (≤3500 RPM). The table cla…
Lockout
Reversed Flow
Reversed Flow. Return temperature reads higher than supply temperature for 10 minutes. The table classifies it as alarm.…
Details
Temp. probe error
Temp. probe error. An internal temperature sensor appears to be shorted or open circuit; triggers if above dual sensors deliver divergent va…
Details
Unhandled error code
Unhandled error code. Reserved for unforeseen conditions. The table classifies it as alarm.…
Details
Blank – screen dark
Blank – screen dark. Blank screen dark; check transformer, replace if damaged; check circuit board for visible damage. The table classifies …
Details
Service mode after update
Controller is stuck in "service" mode after software update. If update fails or no updates applied; restarting returns the boiler to normal …
Details
Water High Limit / Low Water Cutoff won't clear
Error: Water High Limit / Low Water Cutoff won't clear. Boiler is in 1-hour safety lockout. For instructions on clearing errors, see the V10…
Lockout
Outlet Limited
Outlet Limited. Detected greater than 40°F (22°C) difference between inlet and outlet temperature sensors. The table classifies it as warnin…
Details
Remote offline
Remote offline. A boiler defined as a Master cannot detect any subordinate boilers. The table classifies it as warning.…
Details
Unoccupied
Unoccupied. The Occupied box has been unchecked, indicating that the boiler should not fire. The table classifies it as warning.…
Details
Summer
Summer. A thermostat call is detected, but the boiler will not fire because the Outdoor temperature is above the Summer Shutdown temperature…
Details
Failsafe Setpoint
Failsafe Setpoint. Indication that a Subordinate boiler has lost contact with its Master, or a boiler set up for External Control has lost c…
Details
Sensor
Sensor (Inlet/Outlet Sensor, Remote, Loop Sensor, Pressure Switch). Inlet/Outlet Sensor issue detected between calls for heat; treat as corr…
Details
IBC EX Series commercial boilers (manual 120-327E10)
Ignition Trials Exceeded
Ignition trials exceeded error. Ignition failure after 3 tries; boiler has failed to ignite on 3 successive attempts. Boiler is in lockout f…
Lockout
Water High Limit
Water High Limit error. Water temperature exceeds 208°F, or 201°F for 15 sec. Boiler is in hard lockout mode. The table classifies it as ala…
Lockout
Low Water Cutoff
Low Water Cut-off error. The Safety and Ignition module has detected a low water condition. The table classifies it as alarm.…
Lockout
Interlock 1 or 2 Open
Interlock 1 or 2 error. Jumper lead on Interlock terminals of TB2 is loose or compromised; or external safety is in an alarm state. The tabl…
Details
Vent High Limit
Vent High Limit. Exhaust gas temperature exceeds 248°F for 6 seconds, or 232°F for 60 sec. Boiler is in hard lockout mode. The table classif…
Lockout
Max. delta T Exceeded
Max. delta T Exceeded. Outlet is more than 80°F (44°C) above the inlet temperature; outlet is rising faster than 9°F (5°C) per minute. The t…
Details
Fan Pressure
Fan Pressure. The differential air pressure is not between the upper and lower limits corresponding to the maximum allowable flow restrictio…
Details
High/Low Gas Press
High/Low Gas Press (EX-series only). Inlet gas pressure has risen above 20" w.c. or has fallen below 3.5" w.c. Measure and correct the inlet…
Details
Module High Current
Module High Current. Exceeded 24 VAC to SIM and gas valve. The table classifies it as alarm.…
Details
Low Module Current
Low Module Current. Inadequate current to gas valve (starts below 25mA or stays below 20mA). Manual note: applies to the EX 400, 500, not 70…
Details
Low Water Pressure
Low Water Pressure. Inlet water pressure below 4 psi. The table classifies it as alarm.…
Details
Inlet Pres. Sensor
Inlet Pres. Sensor. Inlet water pressure sensor appears to be shorted or disconnected. The table classifies it as alarm.…
Details
See: Status > SIM menu > Status
See: Status > SIM menu > Status. SIM has detected an error that has subsequently cleared. The table classifies it as alarm.…
Details
Roll Out Switch
Roll Out Switch. Rollout switch, by combustion chamber, has detected 230°F temperature. The table classifies it as alarm.…
Details
Controller Board
Controller Board. Error internal to control board; typically result of poor incoming power; may require a reboot. The table classifies it as…
Details
No Boilernet Comm
No Boilernet Comm. Controller set as Master detects a CANbus wiring issue. The table classifies it as alarm.…
Details
No MAC address
No MAC address. Boiler cannot verify a valid MAC address. The table classifies it as alarm.…
Details
[Vent High Pressure]
[Vent High Pressure]. Pressure switch has opened while the boiler is in pre-purge or heating mode. Possible blocked vent. The table classifi…
Details
Flame Signal / Vent Block
Flame Signal / Vent Block. SIM flame current drops below minimum values: EX 400 2.0 μA, EX 500 3.6 μA, EX 700 2.8 μA, EX 850 2.8 μA (≤3500 R…
Lockout
Reversed Flow
Reversed Flow. Return temperature reads higher than supply temperature for 10 minutes. The table classifies it as alarm.…
Details
Temp. probe error
Temp. probe error. An internal temperature sensor appears to be shorted or open circuit; triggers if above dual sensors deliver divergent va…
Details
Unhandled error code
Unhandled error code. Reserved for unforeseen conditions. The table classifies it as alarm.…
Details
Blank – screen dark
Blank – screen dark. Blank screen dark; check transformer, replace if damaged; check circuit board for visible damage. The table classifies …
Details
Service mode after update
Controller is stuck in "service" mode after software update. If update fails or no updates applied; restarting returns the boiler to normal …
Details
Water High Limit / Low Water Cutoff won't clear
Error: Water High Limit / Low Water Cutoff won't clear. Boiler is in 1 hour safety lockout. Reset safety device and cycle boiler power off a…
Lockout
Outlet Limited
Outlet Limited. Detected greater than 40°F (22°C) difference between inlet and outlet temperature sensors. The table classifies it as warnin…
Details
Remote offline
Remote offline. A boiler defined as a Master cannot detect any subordinate boilers. The table classifies it as warning.…
Details
Unoccupied
Unoccupied. The Occupied box has been unchecked, indicating that the boiler should not fire. The table classifies it as warning.…
Details
Summer
Summer. A thermostat call is detected, but the boiler will not fire because the Outdoor temperature is above the Summer Shutdown temperature…
Details
Failsafe Setpoint
Failsafe Setpoint. Indication that a Subordinate boiler has lost contact with its Master, or a boiler set up for External Control has lost c…
Details
Sensor
Sensor (Inlet/Outlet Sensor, Remote, Loop Sensor, Pressure Switch). Inlet/Outlet Sensor issue detected between calls for heat; treat as corr…
Details
IBC DC combi legacy boilers (manual 120-183-A-R11)
E1
Flue gas temperature approaching limit. Supply water temperature too high; ambient temperature too high; check positioning of flue gas senso…
Details
E2
Direct DHW Tank Error - No flow detected when enabling the external DHW pump. Pump failed - replace pump; DHW piping loop air locked - bleed…
Details
E3
S3 - DHW Sensor Open. HC boiler defined as DC; Check wiring; replace sensor. The table classifies it as warning.…
Details
E4
S3 - DHW Sensor Short. Check wiring; replace sensor. The table classifies it as warning.…
Details
E5
S5 - Outdoor Sensor Short. Check wiring; replace sensor. The table classifies it as warning.…
Details
E6
No pressure sensor detected (voltage < 0.25V on orange sense wire, space heating is disabled). No pressure sensor detected (voltage < 0.25V …
Details
E7
Pressure sensor out of range (above 4.25Bar/47psi, space heating is disabled). Pressure sensor out of range (above 4.25Bar/47psi, space heat…
Details
LO P
Boiler loop pressure too low. Bring the system back up to pressure; check pressure sensor; replace pressure sensor. The table classifies it …
Details
POLE
Polarity detection fault. Switch the Line and Neutral wire on the power supply; check grounding; check for high potential on Neutral wire; r…
Details
RF
Physical stress on control board. Loosen control board mounting screws. The table classifies it as warning.…
Details
10, 11, 12, 13, 14
Sensor fault S1 (Supply Sensor, upper left side of the heat exchanger). See below, 1 - Temperature too high; check the positioning of S1; ch…
Lockout
20, 21, 22, 23, 24
Sensor fault S2 (Return Sensor, lower left side of the heat exchanger). Check the positioning of S2; check wiring for break; replace S2. The…
Lockout
0
Sensor fault after self check. Replace S1 and/or S2. The table classifies it as fault (lockout).…
Lockout
1
Temperature too high. Air in system - bleed the system of any remaining air; pump not running - bleed air from and/or replace the pump; insu…
Lockout
2
S1 and S2 interchanged. Check wiring harness; replace S1 or S2. The table classifies it as fault (lockout).…
Lockout
4
No flame signal. Gas valve closed; gas supply pressure too low or drooping under load; gas valve or ignition unit not powered; no or incorre…
Lockout
5
Poor flame signal. Condensate drain blocked; gas supply pressure too low or drooping under load; check ignitor and ignition cable; check gas…
Lockout
6
Flame detection fault. Replace ignition cable + ignitor cap; replace ignition module; replace controller. The table classifies it as fault (…
Lockout
8
Incorrect fan speed. Fan rubbing on casing; wiring between fan and casing; check wiring for poor wire contact; replace fan; replace controll…
Lockout
18
Flue Gas Temperature Sensor Open - Lockout Condition. Inspect heat exchanger for fouling and clean as required; check wiring; replace sensor…
Lockout
19
Flue Gas Temperature Sensor Short - Lockout Condition. Inspect heat exchanger for fouling and clean as required; check wiring; replace senso…
Lockout
29, 30
Gas valve relay faulty. Replace controller. The table classifies it as fault (lockout).…
Lockout
IBC HC legacy boilers (manual 120-185-A-R10)
E1
Flue gas temperature approaching limit. Supply water temperature too high; ambient temperature too high; check positioning of flue gas senso…
Details
E2
Direct DHW Tank Error - No flow detected when enabling the external DHW pump. Pump failed - replace pump; DHW piping loop air locked - bleed…
Details
E3
S3 - DHW Sensor Open. Check HC not defined as DC in Installer Menu; Check wiring; replace sensor. The table classifies it as warning.…
Details
E4
S3 - DHW Sensor Short. Check wiring; replace sensor. The table classifies it as warning.…
Details
E5
S5 - Outdoor Sensor Short. Check wiring; replace sensor. The table classifies it as warning.…
Details
E6
No pressure sensor detected (voltage < 0.25V on orange sense wire, space heating is disabled). No pressure sensor detected (voltage < 0.25V …
Details
E7
Pressure sensor out of range (above 4.25Bar/47psi, space heating is disabled). Pressure sensor out of range (above 4.25Bar/47psi, space heat…
Details
LO P
Boiler loop pressure too low. Bring the system back up to pressure; check pressure sensor; replace pressure sensor. The table classifies it …
Details
POLE
Polarity detection fault. Switch the Line and Neutral wire on the power supply; check grounding; check for high potential on Neutral wire; r…
Details
RF
Physical stress on control board. Loosen control board mounting screws. The table classifies it as warning.…
Details
10, 11, 12, 13, 14
Sensor fault S1 (Supply Sensor, upper left side of the heat exchanger). See below, 1 - Temperature too high; check the positioning of S1; ch…
Lockout
20, 21, 22, 23, 24
Sensor fault S2 (Return Sensor, lower left side of the heat exchanger). Check the positioning of S2; check wiring for break; replace S2. The…
Lockout
0
Sensor fault after self check. Replace S1 and/or S2. The table classifies it as fault (lockout).…
Lockout
1
Temperature too high. Air in system - bleed the system of any remaining air; pump not running - bleed air from and/or replace the pump; insu…
Lockout
2
S1 and S2 interchanged. Check wiring harness; replace S1 or S2. The table classifies it as fault (lockout).…
Lockout
4
No flame signal. Gas valve closed; gas supply pressure too low or drooping under load; gas valve or ignition unit not powered; no or incorre…
Lockout
5
Poor flame signal. Condensate drain blocked; gas supply pressure too low or drooping under load; check ignitor and ignition cable; check gas…
Lockout
6
Flame detection fault. Replace ignition cable + ignitor cap; replace ignition module; replace controller. The table classifies it as fault (…
Lockout
8
Incorrect fan speed. Fan rubbing on casing; wiring between fan and casing; check wiring for poor wire contact; replace fan; replace controll…
Lockout
18
Flue Gas Temperature Sensor Open - Lockout Condition. Inspect heat exchanger for fouling and clean as required; check wiring; replace sensor…
Lockout
19
Flue Gas Temperature Sensor Short - Lockout Condition. Inspect heat exchanger for fouling and clean as required; check wiring; replace senso…
Lockout
29, 30
Gas valve relay faulty. Replace controller. The table classifies it as fault (lockout).…
Lockout
IBC IFIRE-B condensing boilers (manual 241941 Rev. 13)
OUTLET SEN
Outlet sensor error. Check the outlet water sensor and its wiring. The table classifies it as error display (Table AI).…
Details
LIMIT SEN
High-limit sensor error. Check the high-limit sensor and its wiring. The table classifies it as error display (Table AI).…
Details
INLET SEN
Inlet sensor error. Check the inlet sensor and its wiring. The table classifies it as error display (Table AI).…
Details
GAS PRESS
Gas pressure error. Check PIM wiring. The table classifies it as error display (Table AI).…
Details
IGNITION
Ignition error. Reset control, push and release RESET button. The table classifies it as error display (Table AI).…
Lockout
LIMIT TRIP
High-limit trip. Heater temperature tripped the high-limit. The table classifies it as error display (Table AI).…
Details
FLAME
False flame detected. False flame detected. Shut off gas supply, recycle power. The table classifies it as error display (Table AI).…
Lockout
ID CARD
Identity card error. Identity card, check ID card and wiring. The table classifies it as error display (Table AI).…
Details
IGN CTRL
Internal control fault. Internal control fault. Reset power, replace control. The table classifies it as error display (Table AI).…
Details
DELTA T
Delta T exceeded. Temperature difference between the inlet and outlet exceeded the setpoint. Check water flow. The table classifies it as er…
Details
LOW 24VAC
Low 24 VAC power. Low 24 VAC power. Check power supply wiring and transformer. The table classifies it as error display (Table AI).…
Details
BLOW SPEED
Blower speed out of range. Blower speed out of range. Check blower wiring and blower. The table classifies it as error display (Table AI).…
Details
FLOW ERROR
Flow error. The unit is not detecting enough flow to allow ignition sequence to take place. The table classifies it as error display (Table …
Lockout
UNDER FLOW
Under flow. The flow reading has drop under minimum requirements to keep the current operation point. The table classifies it as error displ…
Details
FLOW WARNING
Flow warning. Operation conditions do not match current flow reading. The table classifies it as error display (Table AI).…
Details
Red LED Steady ON
ID Card Fault. Check that the proper ID Card is securely connected. Perform a power and system reset. The table classifies it as fault (PIM …
Details
Red LED Steady ON
Internal Control Fault. Perform a power and system reset. If the fault remains, replace the PIM. The table classifies it as fault (PIM LED).…
Details
Red LED - 1 Flash
N/A. N/A. The table classifies it as fault (PIM LED).…
Details
Red LED - 2 Flashes
False Flame Error. Check for proper gas valve closure. Clean burner and electrodes. The table classifies it as fault (PIM LED).…
Lockout
Red LED - 3 Flashes
Ignition Lockout Fault. Check the gas supply. Check transformer. Check igniters. Check wiring. Press reset button on PIM/membrane switch. Re…
Lockout
Red LED - 4 Flashes
Ignition Proving Current Fault. Check DSI element. Replace as necessary. The table classifies it as fault (PIM LED).…
Lockout
Red LED - 5 Flashes
Low Voltage Fault. Check the 24VAC input voltage - the voltage must be above 18.0VAC for proper operation. Replace transformer as necessary.…
Details
Red LED - 6 Flashes
N/A. N/A. The table classifies it as fault (PIM LED).…
Details
Red LED - 7 Flashes
Hi-Limit Fault. Check for proper water flow. Check hi-limit setting and outlet sensor. The table classifies it as fault (PIM LED).…
Details
Red LED - 8 Flashes
Sensor Fault. Check the VERSA IC for fault identification. Check sensor and wiring. The table classifies it as fault (PIM LED).…
Details
Red LED - 9 Flashes
N/A. Check wiring at J8, pins 1 and 3 for loose or missing jumper. The table classifies it as fault (PIM LED).…
Details
Red LED - 10 Flashes
Water Pressure Fault. Check system piping for leaks. Check water pressure switch (if equipped) and connections. Check wiring on PIM at J1, p…
Details
Red LED - 11 Flashes
Blower Speed Fault. Verify the tachometer signal and the connections at terminals J10 on the PIM. Confirm power to heater is at or above min…
Details
Red LED - 12 Flashes
N/A. Check wiring on PIM at J1, pins 3 and 4 for loose or missing jumper. The table classifies it as fault (PIM LED).…
Details
Red LED - 13 Flashes
Hi-Temperature Delta Fault. Check pumps operation. Confirm proper water flow across heat exchanger (Delta T). The table classifies it as fau…
Details
Red LED - 14 Flashes
Ft_bus Communications Fault. Verify that the VERSA IC is connected and operating properly. Check the cable between the PIM and the VERSA IC.…
Details
Red LED - 15 Flashes
General limit circuit fault. Check the VERSA IC for fault indication and troubleshooting information. The table classifies it as fault (PIM …
Details
Talk to a boiler technician
Describe what the boiler is doing and get a straight answer about the next step.
On-site service in Greater Vancouver, BC. ROMA lists “Open 7 days” on its site; call to confirm same-day availability.