BoilerFaultCodes Last 28 days · Real search data
Most-searched boiler fault codes
The fault codes UK boiler owners actually look up — ranked by what's most searched on the site. Each entry links to the full plain-English explanation, repair cost estimate, and severity.
| # | Code | What it means | Severity | Searches |
|---|---|---|---|---|
| 1 | E10 Baxi Duo-tec/Megaflo | Your boiler has lost communication with the sensor that monitors the temperature outside your home, preventing it from adjusting its heat output efficiently. ~£90-160 | Low | 0 clicks 1 impressions |
| 2 | E110 Baxi Duo-tec/Megaflo | Your boiler has become too hot and has shut itself down as a safety precaution to prevent damage. ~£100-£350 | High | 0 clicks 1 impressions |
| 3 | E28 Baxi Duo-tec/Megaflo | Your boiler has detected a problem with the sensor that monitors the temperature of the exhaust gases, causing the system to shut down for safety. ~£120-£220 | High | 0 clicks 1 impressions |
| 4 | F000 Intergas Xtreme / Xclusive | Your boiler has stopped working because one of its internal sensors is sending an incorrect signals or has disconnected, preventing it from heating your water safely. ~£120-£220 | High | 0 clicks 1 impressions |
| 5 | E118 Main Eco Compact | Your boiler has stopped working because the water pressure in the system has dropped too low and needs topping up. ~£0-120 | High | 0 clicks 1 impressions |
| 6 | E76 Alpha E-Tec | Your boiler's internal fuel control system is experiencing an electrical measurement error, causing it to shut down for safety reasons. ~£180-350 | High | 0 clicks 1 impressions |
| 7 | 23 Alpha Evoke | Your boiler is struggling to accurately measure the temperature of the water coming back into the system, so it has safely shut down to prevent overheating. ~£150-250 | High | 0 clicks 2 impressions |
| 8 | E27 Alpha Evoke | Your boiler is struggling to move enough water through your heating system, which usually means there is a blockage or the internal pump is failing. ~£150-350 | High | 0 clicks 1 impressions |
| 9 | flame failure Ariston Clas One | Your boiler is trying to start but cannot detect a flame, meaning it is currently unable to provide heating or hot water. ~£120-250 | High | 0 clicks 2 impressions |
| 10 | HIGH Atag E32S | Your boiler has detected that the water pressure in your heating system is too high, which could cause a leak or damage if not addressed. | High | 0 clicks 1 impressions |
| 11 | DHW Fault Baxi 130 HE (range) | Your boiler has detected a problem with the domestic hot water system, meaning you likely have no hot water but your central heating may still function. ~£120-£250 | Medium | 0 clicks 1 impressions |
| 12 | FAN Baxi 130 HE (range) | Your boiler has detected an internal electrical communication error or a potential component failure preventing the fan from starting safely. ~£250-450 | High | 0 clicks 1 impressions |
| 13 | L2 Baxi 130 HE (range) | Your boiler has stopped working because it is unable to accurately measure the temperature of the water flowing through the system. ~£120-220 | High | 0 clicks 2 impressions |
| 14 | Lights Flash Off On Baxi 130 HE (range) | Your boiler has switched itself off because it has become too hot internally, usually due to a lack of water flow or a circulation error. ~£120-£350 | High | 0 clicks 1 impressions |
| 15 | PCB Fault Baxi 130 HE (range) | Your boiler's internal computer brain has detected an electronic error and has stopped working to protect the system. ~£250-450 | High | 0 clicks 1 impressions |
| 16 | E.01 – .17 Baxi 200 / 400 Combi | Your boiler has stopped working because water isn't moving through the system correctly or a internal sensor has lost its connection. ~£120-280 | High | 0 clicks 1 impressions |
| 17 | 1 green flash Baxi EcoBlue | Your boiler has reached the correct temperature and is simply taking a natural rest; it is working exactly as it should. | Low | 0 clicks 2 impressions |
| 18 | 3 red flashes Baxi EcoBlue | Your boiler has tried to light itself several times but cannot establish a flame, meaning you will have no heating or hot water until it is reset or repaired. ~£120-280 | High | 0 clicks 1 impressions |
| 19 | 5 red flashes Baxi EcoBlue | Your boiler's internal memory chip has developed a communication fault, meaning the control board can no longer read its essential settings. ~£120-250 | High | 0 clicks 2 impressions |
| 20 | Flame Failure Reset Button Baxi Main Combi 24 | Your boiler has stopped working because it couldn't light the flame, so it has safely shut itself down. ~£120-250 | High | 0 clicks 1 impressions |
| 21 | 4 Green Flashes Baxi MainEco | Your boiler is temporarily struggling to talk to its internal control parts and is trying to reconnect itself. ~£0-280 | Low | 0 clicks 1 impressions |
| 22 | 153 Baxi Profile Prima | Your boiler has likely experienced a technical internal error or a safety lockout that has been manually cleared, but the system is now failing to restart correctly. ~£100-350 | High | 0 clicks 1 impressions |
| 23 | 4 green flashes Baxi Profile Prima | Your boiler has temporarily lost communication between its internal electronic parts but should automatically try to restart itself shortly. ~£180-350 | Low | 0 clicks 1 impressions |
| 24 | E.01 – .17 Baxi Profile Prima | Your boiler has stopped working because water is not moving through the system properly or a sensor has lost connection. ~£90-250 | High | 0 clicks 4 impressions |
| 25 | 4 red flashes Baxi Profile | Your boiler has stopped working because the fan that helps remove waste gases is not spinning correctly or has lost power. ~£180-350 | High | 0 clicks 1 impressions |
| 26 | Boiler On (Orange LED) Baxi Solo 3 40 PF | Your boiler is operating normally and the orange light simply indicates that the burner is currently lit and heating your water. | Low | 0 clicks 1 impressions |
| 27 | Lockout Baxi Solo 3 40 PF | Your boiler has automatically shut down to protect itself, likely because it got too hot or experienced a temporary glitch. ~£90-180 | High | 0 clicks 1 impressions |
| 28 | Fan On Baxi Solo 3 PFL | Your boiler is operating normally, and this indicator light simply shows that the internal fan is running as expected to vent the system. | Low | 0 clicks 2 impressions |
| 29 | F5 Ferroli Optima 201 | Your boiler has stopped working because it cannot detect that the internal fan, which is essential for safely venting exhaust gases, is spinning correctly. ~£180-350 | High | 0 clicks 1 impressions |
| 30 | FH Ferroli Optima 201 | Your boiler is currently performing a brief automatic self-test to clear any trapped air from the system and will usually resume normal operation on its own after two minutes. | Low | 0 clicks 2 impressions |
| 31 | F9 Glow-worm 30ci Plus | Your boiler has stopped working because it cannot correctly detect the water pressure, which is usually caused by a faulty internal sensor rather than a leak. ~£120-190 | High | 0 clicks 2 impressions |
| 32 | F.22 Glow-worm 38cxi | Your boiler has stopped working because there is not enough water pressure in the system to operate safely. ~£0-120 | High | 0 clicks 1 impressions |
| 33 | Red flashing light (Gas) Glow-worm Compact | Your boiler has stopped working because it cannot get a steady supply of gas to stay lit. ~£100-£350 | High | 0 clicks 1 impressions |
| 34 | Red light (flashing) Glow-worm Swift Flow 100 | Your boiler has encountered an internal error and needs a simple restart to try and clear the fault. ~£90-280 | High | 0 clicks 1 impressions |
| 35 | F75 Glow-worm Ultracom 24cx 30cx | Your boiler has stopped working because it cannot detect the necessary change in water pressure required to safely start the heating process. ~£140-350 | High | 0 clicks 1 impressions |
| 36 | F5 Heatline Capriz 25 System | Your boiler is struggling to ensure the air required for the combustion process is flowing correctly through the system safely. ~£150-250 | High | 0 clicks 1 impressions |
| 37 | FLAME FAILURE LED Ideal Boxer | Your boiler has tried to start but could not get the fire going or keep it lit, so it has safely shut itself down. ~£120-250 | High | 0 clicks 2 impressions |
| 38 | FLAME FAILURE LED Ideal Europa | Your boiler has attempted to start but could not ignite the fuel, so it has shut down to keep your home safe. ~£120-250 | High | 0 clicks 2 impressions |
| 39 | H A (flashing) Ideal Icos | Your boiler has stopped working because the water pressure inside the heating system has dropped too low to operate safely. | High | 0 clicks 1 impressions |
| 40 | L 0d Ideal Logic Code Combi ESP1 | Your boiler has stopped working because it cannot safely get rid of exhaust fumes or waste water, often due to a blockage or a frozen pipe. ~£100-280 | High | 0 clicks 2 impressions |
| 41 | L1 Ideal Logic Code Combi ESP1 | Your boiler has switched itself off because the internal water temperature has become too hot, usually caused by a lack of water flow through the system. ~£120-£350 | High | 0 clicks 1 impressions |
| 42 | P7 Ideal Logic Code Combi ESP1 | Your boiler is displaying a configuration message regarding how fast its internal pump should run to move water through your radiators. ~£0-80 | Low | 0 clicks 1 impressions |
| 43 | PCB REPLACED Ideal Logic Code Combi ESP1 | Your boiler has recently had its main circuit board changed and simply needs a quick reset to finish the setup process. | High | 0 clicks 2 impressions |
| 44 | 4.7 Ideal Logic Max Heat 2 | Your boiler detects a flame when it should be off, which is a safety error that prevents the system from starting up. ~£180-450 | High | 0 clicks 1 impressions |
| 45 | L2 Ideal Logic Max & Logic Plus | Your boiler has failed to light several times and has shut down for safety, meaning you currently have no heating or hot water. ~£100-£350 | High | 0 clicks 1 impressions |
| 46 | L1 Ideal Vogue | Your boiler has stopped working because the internal temperature has become too high or water is not circulating through the system properly. ~£120-350 | High | 0 clicks 2 impressions |
| 47 | f014 Intergas Xtreme | Your boiler has detected that a temperature sensor is not attached correctly or has become loose, preventing the system from heating up safely. ~£90-180 | High | 0 clicks 1 impressions |
| 48 | E37 Keston C36p | Your boiler has stopped working because the water pressure inside the heating system has dropped too low. | High | 0 clicks 1 impressions |
| 49 | E291 Navien NCB | Your boiler has detected that the hot water flow and the cooler return water are being identified in the wrong order, likely due to a sensor misreading or a plumbing configuration issue. ~£120-250 | High | 0 clicks 1 impressions |
| 50 | Fan Purge Potterton Envoy 30 | Your boiler is currently running a process to clear any leftover gases from the burn chamber before it attempts to light, which is a normal safety routine. | Low | 0 clicks 1 impressions |
| 51 | Flame Failure Potterton Performa 24 Eco HE | Your boiler has stopped working because it cannot light its internal flame, which means you currently have no heating or hot water. ~£120-250 | High | 0 clicks 5 impressions |
| 52 | Circulation LOCKOUT Potterton Suprima HE | Your boiler has detected that hot water isn't moving around your radiators or pipes properly and has shut itself down to prevent overheating. ~£150-350 | High | 0 clicks 2 impressions |
| 53 | Green light flashing slowly Potterton Suprima HE | Your boiler is currently in standby mode and is working correctly, simply waiting for a signal from your thermostat or timer to start heating. | Low | 0 clicks 1 impressions |
| 54 | PCB Fault Potterton Suprima HE | Your boiler's internal computer has stopped working correctly and is no longer able to safely manage the heating system. ~£250-400 | High | 0 clicks 1 impressions |
| 55 | E08 Ravenheat Csi Primary | Your boiler has detected that there is not enough water in the system to operate safely and has shut down to prevent damage. ~£0-160 | High | 0 clicks 1 impressions |
| 56 | E02 Remeha Avanta Plus | Your boiler has shut down because the water inside has become far too hot, which is often caused by a blockage or a pump that isn't moving water around the system properly. ~£150-£350 | High | 0 clicks 1 impressions |
| 57 | E10 Remeha Avanta Plus | Your boiler has stopped working because the water pressure inside the system has dropped too low to operate safely. ~£0-120 | High | 0 clicks 1 impressions |
| 58 | E36 Remeha Avanta Plus | Your boiler's main internal computer has developed a communication or electronic fault, causing the system to stop working for safety. ~£280-450 | High | 0 clicks 1 impressions |
| 59 | 02 Saunier Duval Isofast | Your boiler is struggling to clear exhaust fumes or draw in fresh air, so it has safely shut down to prevent any risk. ~£150-300 | High | 0 clicks 1 impressions |
| 60 | F5 Saunier Duval Isotwin F30E | Your boiler has switched itself off because it has reached an unsafe temperature to protect the internal components from damage. ~£120-300 | High | 0 clicks 1 impressions |
Don't see your code?
We track all 17,000+ fault codes across every UK boiler brand — search by code, model, or symptom on the homepage.