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Ariston Fault Codes
Select a fault code to see its meaning, common causes and how to fix it.
- 101 Fault code 101 on an Ariston boiler indicates that the central heating circuit has reached a dangerously high… Read more →
- 102 Fault code 102 on Ariston boilers signals that the heating circuit pressure sensor has detected either an open circuit… Read more →
- 103 Ariston fault code 103 signals that the boiler has detected insufficient water circulation through the heating system.… Read more →
- 104 Ariston fault code 104 is a safety lockout triggered when the boiler detects that water is not circulating properly… Read more →
- 105 Fault code 105 on an Ariston boiler signals that the boiler has detected a dangerously large temperature gap between… Read more →
- 106 Fault code 106 on Ariston boilers signals an insufficient circulation problem. The boiler's control system has detected… Read more →
- 107 Fault code 107 on Ariston boilers signals an 'Insufficient Circulation' condition. The boiler's onboard monitoring has… Read more →
- 108 Fault code 108 on an Ariston boiler indicates that the water pressure inside the central heating circuit has fallen… Read more →
- 109 Fault code 109 on Ariston boilers indicates that the system water pressure has climbed above 3 bar, triggering a safety… Read more →
- 110 Fault code 110 on Ariston boilers indicates that the central heating flow temperature probe has developed an open or… Read more →
- 111 Fault code 111 signals that your Ariston boiler has detected water pressure in the heating system has dropped below the… Read more →
- 112 Fault code 112 appears on Ariston boilers when the control board detects a problem with the central heating return… Read more →
- 114 Fault code 114 on Ariston boilers signals a problem with the external (outdoor) temperature sensor circuit.… Read more →
- 116 Ariston fault code 116 points to a problem with the room temperature sensor circuit or, on certain models, an open… Read more →
- 118 Fault code 118 on Ariston boilers most commonly signals that the boiler's heating delivery (flow) temperature probe has… Read more →
- 1P1 The 1P1 code is Ariston's early-warning signal that water isn't flowing through the heating system as well as it should… Read more →
- 1P2 The 1P2 code appears on Ariston boilers when the boiler's internal sensors detect that water is not moving around the… Read more →
- 1P3 The 1P3 code on an Ariston boiler is an early-warning indicator that water is not circulating properly around the… Read more →
- 1P4 The 1P4 code on an Ariston boiler is an early-warning alert rather than a hard lockout. It signals that the boiler has… Read more →
- 201 Fault code 201 on an Ariston boiler signals a problem with the domestic hot water (DHW) NTC temperature sensor circuit.… Read more →
- 202 Ariston fault code 202 belongs to the 200-series, which covers domestic hot water (DHW) circuit sensor faults. On most… Read more →
- 203 Fault code 203 on Ariston boilers indicates that the control board (PCB) has lost its signal from the hot water… Read more →
- 204 Fault code 204 on Ariston boilers signals that the NTC thermistor (temperature sensor) monitoring the hot water storage… Read more →
- 205 Fault code 205 on Ariston boilers signals that the domestic hot water (DHW) inlet temperature probe has lost its… Read more →
- 206 Fault code 206 on Ariston boilers signals that the NTC temperature sensor positioned at the solar inlet to the domestic… Read more →
- 207 Fault code 207 on an Ariston boiler indicates that the solar collector pipework has reached an excessively high… Read more →
- 208 Fault code 208 on Ariston boilers signals that the solar collector circuit has detected an abnormally low temperature.… Read more →
- 209 Ariston fault code 209 is a safety lockout triggered when the boiler's processor detects that the hot water storage… Read more →
- 301 Fault code 301 on an Ariston boiler signals a problem with the EEPROM — the small memory chip embedded on the main… Read more →
- 302 Fault code 302 on an Ariston boiler signals an internal communication error — the main printed circuit board (PCB) has… Read more →
- 303 Fault code 303 on an Ariston boiler indicates an internal fault with the main Printed Circuit Board (PCB) — the… Read more →
- 304 Ariston fault code 304 is a safety lockout triggered when the boiler has been reset too many times in a short period.… Read more →
- 305 Fault code 305 on an Ariston boiler signals an internal block error within the electronic control board (ECB), also… Read more →
- 306 Fault code 306 on Ariston boilers points to one of two possible issues depending on your specific model and firmware… Read more →
- 307 Fault code 307 on an Ariston boiler signals an internal fault with the electronic control board (ECB), also known as… Read more →
- 3P9 The 3P9 code on Ariston boilers is not a fault or error — it is a scheduled service reminder. It appears when the… Read more →
- 407 Fault code 407 on an Ariston boiler points to a problem with the room temperature sensor circuit. The boiler's control… Read more →
- 411 Fault code 411 on Ariston boilers indicates that the control board has lost communication with the Zone 1 room (ambient… Read more →
- 412 Ariston fault code 412 belongs to the '4' functional group, which covers communication, modem, and room sensor… Read more →
- 414 Fault code 414 (displayed as '4 14' on the boiler's screen) tells you that the boiler's control system has lost… Read more →
- 501 Fault code 501 on an Ariston boiler means the boiler attempted to light the burner but received no confirmation that a… Read more →
- 502 Ariston fault code 502 indicates that the boiler's flame detection system is registering a flame signal at a point when… Read more →
- 504 Fault code 504 on an Ariston boiler indicates a flame lift problem — the burner flame has become unstable or has gone… Read more →
- 507 If your Ariston boiler display is showing '507', it is worth taking a second look — this code does not appear in… Read more →
- 5P1 The 5P1 code appears on Ariston boilers when the burner fails to ignite on the first attempt. Because Ariston's… Read more →
- 5P2 The 5P2 fault code means your Ariston boiler attempted to light the burner twice and failed on both occasions,… Read more →
- 5P3 The 5P3 fault code on Ariston boilers indicates that the burner flame went out while the boiler was already running —… Read more →
- 5P4 The 5P4 code appears when your Ariston boiler has attempted to ignite or hold a flame three times within a single… Read more →
- 601 Ariston fault code 601 sits within the 600-series, which covers flue, fan, and air pressure switch issues — all… Read more →
- 604 Fault code 604 on Ariston boilers indicates that the fan is not reaching the speed required for safe operation, or that… Read more →
- 607 Fault code 607 on an Ariston boiler means the air pressure switch has registered a closed (active) state before the fan… Read more →
- 608 Fault code 608 indicates that the boiler's fan has started up as normal, but the air pressure switch has failed to… Read more →
- 610 Ariston fault code 610 sits within the boiler's Group 6 fault category, which covers faults associated with the air… Read more →
- 612 Fault code 612 on Ariston boilers signals a fan fault that has escalated beyond the initial warning stage. The '6'… Read more →
- 6P1 The 6P1 fault code on Ariston boilers signals that the air pressure switch (also called the differential pressure… Read more →
- 6P2 The 6P2 code appears on Ariston boilers when the air pressure switch fails to maintain its signal while the boiler is… Read more →
- 701 Fault code 701 on Ariston boilers signals a problem with a flow or outgoing temperature sensor, though the exact sensor… Read more →
- 702 Fault code 702 on Ariston boilers has two distinct meanings depending on your model. On multi-zone models such as the… Read more →
- 703 Fault code 703 appears on certain Ariston boilers to indicate that the temperature sensor monitoring the outgoing… Read more →
- 704 Fault code 704 tells you that the boiler has detected a problem with the NTC thermistor (temperature sensor) fitted to… Read more →
- 705 On Ariston Sensys and multi-zone system boilers, the display can show what appears to be '705' but is actually the… Read more →
- 706 Fault code 706 appears on Ariston E-Combi Evo, E-System Evo, Clas HE Evo Combi, and Clas HE Evo System boilers when the… Read more →
- 707 Fault code 707 on Ariston boilers signals that the boiler's safety system has detected dangerously high temperatures in… Read more →
- 711 Ariston fault code 711 (shown on the display as '7 11') indicates a problem with the Zone 1 return temperature sensor —… Read more →
- 712 Fault code 712 on Ariston boilers indicates that the control board has detected a problem with the Zone 2 return… Read more →
- 713 Fault code 713 on an Ariston boiler indicates that the control board has detected a problem with the Zone 3 return… Read more →
- 722 Fault code 722 on Ariston boilers has two distinct meanings depending on which model you own — always check the data… Read more →
- 723 Fault code 723 indicates that the boiler has detected an overheat condition in heating Zone 3. The system's temperature… Read more →
- 750 Fault code 750 on Ariston boilers indicates that the boiler's control board cannot identify or confirm the hydraulic… Read more →