IVT
IVT Boilers Error Codes
Complete list of fault codes and troubleshooting guides. Use the search below to find your specific error.
Advertisements
A01
Boiler locks out with A01 on display, burner does not ignite, fan may start briefly then stop
Ignition Failure / No Flame Detection
A02
Boiler shows A02 and shuts down shortly after ignition, flame lights but then goes out
Flame Loss During Operation
A03
Boiler displays A03 and will not start, fan does not run or runs briefly then stops
Flue Gas Safety / Flue Gas Sensor Trip
A04
Boiler shows A04, no heating or hot water, pump may run briefly then stop
Low Water Pressure / Water Shortage
A05
Boiler locks out with A05, overheating, may make boiling or kettling noises before shutdown
Primary Circuit Overheat / Safety Thermostat Trip
A06
Boiler shows A06, fan runs but ignition sequence does not start
Air Pressure Switch / Fan Proving Fault
A07
Boiler displays A07, no heating or hot water, pump may run continuously
Flow Temperature Sensor Fault (NTC Open/Short)
A08
Boiler shows A08, temperature reading on display is unrealistic (very high or very low)
Return Temperature Sensor Fault (NTC Open/Short)
A09
Boiler displays A09, domestic hot water temperature unstable or incorrect
DHW Temperature Sensor Fault
A10
Boiler shows A10, will not start, pressure reading on display is unrealistic or fixed
Water Pressure Sensor Electrical Fault
A11
Boiler displays A11, fan does not start, no ignition attempt
Fan Motor / Fan Control Fault
A12
Boiler shows A12, no response to thermostat or control signals
Communication Fault with Room Controller / Bus Error
A13
Boiler displays A13, burner shuts down and restarts frequently (short cycling)
Flow Rate / Delta-T Regulation Fault
A14
Boiler shows A14, no hot water, heating may still work
DHW Flow Switch / Flow Sensor Fault
A15
Boiler displays A15, burner does not start, gas supply appears normal
Gas Valve Control / Internal Gas Valve Fault
A16
Boiler shows A16, display may flicker or reboot, random lockouts
Mains Supply / Low Voltage Fault
A17
Boiler displays A17, condensate may be visible around base of boiler
Condensate Pump / Condensate Level Fault (if fitted)
A18
Boiler shows A18, heating flow temperature rises too quickly then burner shuts down
Pump Flow Fault / Pump Speed Error
A19
Boiler displays A19, hot water temperature overshoots setpoint significantly
DHW Overtemperature / Regulation Fault
A20
Boiler shows A20, heating demand present but burner does not start, 3-way valve may move
3-Way Diverter Valve Position Fault
Symptom
Boiler casing vibrates and rattles during operation
Mechanical Vibration / Loose Panels
Symptom
Boiler condensate pipe repeatedly freezes in cold weather
Condensate Drain Freezing
Symptom
Boiler display is blank but fused spur is on
No Power to Control Panel
Symptom
Boiler does not respond to room thermostat, heating stays off
Control Signal / Thermostat Fault
Symptom
Boiler emits a burning smell or visible smoke from casing
Electrical Overheating / Component Failure
Symptom
Boiler fan is very noisy during operation
Fan Bearing Wear / Imbalance
Symptom
Boiler frequently air-locks and needs bleeding
Air Ingress / Venting Problem
Symptom
Boiler frequently needs resetting to restore operation
Intermittent Lockout / Unstable Operation
Symptom
Boiler ignites with a loud bang (hard light)
Delayed Ignition
Symptom
Boiler leaking water from underneath the casing
Internal Water Leak
Symptom
Boiler loses pressure over time without visible leaks
Hidden System Leak / Micro-Leak
Symptom
Boiler makes loud banging or knocking noises when starting or stopping
Kettling / Hydraulic Shock
Symptom
Boiler pressure rises rapidly when heating is on and discharges water from the safety valve
Expansion Vessel Failure / Overpressure
Symptom
Boiler runs but domestic hot water is lukewarm or fluctuates in temperature
DHW Performance / Heat Transfer Issue
Symptom
Boiler runs continuously and overheats the house even when thermostat is turned down
Control Stuck On / Relay Fault
Symptom
Radiators are not heating properly even though boiler runs
Poor Circulation / System Balancing Issue
| Error Code | Symptom | Fault Type | Guide |
|---|---|---|---|
| A01 |
Boiler locks out with A01 on display, burner does not ignite, fan may start briefly then stop
|
Ignition Failure / No Flame Detection | View Details |
| A02 |
Boiler shows A02 and shuts down shortly after ignition, flame lights but then goes out
|
Flame Loss During Operation | View Details |
| A03 |
Boiler displays A03 and will not start, fan does not run or runs briefly then stops
|
Flue Gas Safety / Flue Gas Sensor Trip | View Details |
| A04 |
Boiler shows A04, no heating or hot water, pump may run briefly then stop
|
Low Water Pressure / Water Shortage | View Details |
| A05 |
Boiler locks out with A05, overheating, may make boiling or kettling noises before shutdown
|
Primary Circuit Overheat / Safety Thermostat Trip | View Details |
| A06 |
Boiler shows A06, fan runs but ignition sequence does not start
|
Air Pressure Switch / Fan Proving Fault | View Details |
| A07 |
Boiler displays A07, no heating or hot water, pump may run continuously
|
Flow Temperature Sensor Fault (NTC Open/Short) | View Details |
| A08 |
Boiler shows A08, temperature reading on display is unrealistic (very high or very low)
|
Return Temperature Sensor Fault (NTC Open/Short) | View Details |
| A09 |
Boiler displays A09, domestic hot water temperature unstable or incorrect
|
DHW Temperature Sensor Fault | View Details |
| A10 |
Boiler shows A10, will not start, pressure reading on display is unrealistic or fixed
|
Water Pressure Sensor Electrical Fault | View Details |
| A11 |
Boiler displays A11, fan does not start, no ignition attempt
|
Fan Motor / Fan Control Fault | View Details |
| A12 |
Boiler shows A12, no response to thermostat or control signals
|
Communication Fault with Room Controller / Bus Error | View Details |
| A13 |
Boiler displays A13, burner shuts down and restarts frequently (short cycling)
|
Flow Rate / Delta-T Regulation Fault | View Details |
| A14 |
Boiler shows A14, no hot water, heating may still work
|
DHW Flow Switch / Flow Sensor Fault | View Details |
| A15 |
Boiler displays A15, burner does not start, gas supply appears normal
|
Gas Valve Control / Internal Gas Valve Fault | View Details |
| A16 |
Boiler shows A16, display may flicker or reboot, random lockouts
|
Mains Supply / Low Voltage Fault | View Details |
| A17 |
Boiler displays A17, condensate may be visible around base of boiler
|
Condensate Pump / Condensate Level Fault (if fitted) | View Details |
| A18 |
Boiler shows A18, heating flow temperature rises too quickly then burner shuts down
|
Pump Flow Fault / Pump Speed Error | View Details |
| A19 |
Boiler displays A19, hot water temperature overshoots setpoint significantly
|
DHW Overtemperature / Regulation Fault | View Details |
| A20 |
Boiler shows A20, heating demand present but burner does not start, 3-way valve may move
|
3-Way Diverter Valve Position Fault | View Details |
| – |
Boiler casing vibrates and rattles during operation
|
Mechanical Vibration / Loose Panels | View Details |
| – |
Boiler condensate pipe repeatedly freezes in cold weather
|
Condensate Drain Freezing | View Details |
| – |
Boiler display is blank but fused spur is on
|
No Power to Control Panel | View Details |
| – |
Boiler does not respond to room thermostat, heating stays off
|
Control Signal / Thermostat Fault | View Details |
| – |
Boiler emits a burning smell or visible smoke from casing
|
Electrical Overheating / Component Failure | View Details |
| – |
Boiler fan is very noisy during operation
|
Fan Bearing Wear / Imbalance | View Details |
| – |
Boiler frequently air-locks and needs bleeding
|
Air Ingress / Venting Problem | View Details |
| – |
Boiler frequently needs resetting to restore operation
|
Intermittent Lockout / Unstable Operation | View Details |
| – |
Boiler ignites with a loud bang (hard light)
|
Delayed Ignition | View Details |
| – |
Boiler leaking water from underneath the casing
|
Internal Water Leak | View Details |
| – |
Boiler loses pressure over time without visible leaks
|
Hidden System Leak / Micro-Leak | View Details |
| – |
Boiler makes loud banging or knocking noises when starting or stopping
|
Kettling / Hydraulic Shock | View Details |
| – |
Boiler pressure rises rapidly when heating is on and discharges water from the safety valve
|
Expansion Vessel Failure / Overpressure | View Details |
| – |
Boiler runs but domestic hot water is lukewarm or fluctuates in temperature
|
DHW Performance / Heat Transfer Issue | View Details |
| – |
Boiler runs continuously and overheats the house even when thermostat is turned down
|
Control Stuck On / Relay Fault | View Details |
| – |
Radiators are not heating properly even though boiler runs
|
Poor Circulation / System Balancing Issue | View Details |
No matching codes found
Advertisements