With over four decades of experience in the industry, Maintracts Services has become a trusted name when it comes to the installation, service, and repair of Viessmann boilers. In today’s blog post, we’ll be discussing common Viessmann boiler error codes, shedding light on what they mean and how to troubleshoot them. As a heating engineer, I’ve encountered these error codes countless times and have the expertise to help you navigate through them effectively. So, whether you’re a homeowner, landlord, or a heating professional, keep reading to unravel the mysteries behind those perplexing Viessmann boiler error codes!
Main Boiler Fault Codes
| Code | Possible Fault | User Action |
| E20, E28, E50 and E160 | Faulty components | You should make a note of the displayed error code and contact Maintracts Services or Baxi customer support. |
| E110 | Displayed overheat of the primary water or flue system has occurred | Turn the selector switch to the reset position and hold for at least 5 seconds. If the boiler does not relight, or the code is displayed regularly contact Maintracts Services or Baxi Customer Support. |
| E119 | Displayed when the primary water pressure is less than 0.5 bar | You can repressurise the boiler yourself. |
| E133 | Indicates that the gas supply has been interrupted, ignition has failed, or the flame has not been detected | Ensure that the gas supply has not been turned off and turn the selector switch to the reset position and hold for at least 5 seconds. If the boiler does not relight, or the code is displayed. Regularly contact Maintracts Services or Baxi Customer Support. |
| E133 | Can also display in the winter if the condensate pipe of your boiler has frozen | The boiler will switch off to protect itself. You can find out how to thaw your condensate pipe by watching this |
| E168 | Could mean that your boiler has detected a problem but can’t work out exactly what it is. This could be because the boiler has been reset after developing a fault or because there has been an external issue, such as a fault with the electrical supply | The boiler might have been displaying a different error code prior to resetting, so it is useful to make a note of any error codes you see as this will help your installer identify the issue. Call Maintracts Services or Baxi Customer Support if E168 persists. |
| Fault code | System behaviour |
| E168 | Error code E168 could mean that your boiler has detected a problem but can’t work out exactly what it is; |
| E20 | Central Heating NTC Fault indicate faulty components. You should make a note of the displayed error code |
| E28 | PCB Fault indicate faulty components |
| E50 | Hot Water NTC Fault indicate faulty components |
| E110 | Safety Thermostat operated – displayed when the primary water pressure is less than 0.5 bar. After repressurising the system the boiler should operate. Your installer will be able to advise you about the method of repressurising. |
| E119 | Water pressure switch not operated – displayed when the primary water pressure is less than 0.5 bar. After repressurising the system the boiler should operate. Your installer will be able to advise you about the method of repressurising |
| E33 | Interruption Of Gas Supply or Flame Failure indicates that the gas supply has been interrupted, ignition has failed, or the flame has not been detected. Ensure that the gas supply has not been turned off and turn the selector switch to the reset position and hold for at least 5 seconds. If the boiler does not relight, or the code is displayed regularly. |
| E60 | Fan or fan wiring fault |
Main Eco Compact Boiler
| Fault code | System behaviour |
| E09 | Gas valve connection error |
| E15v | Gas valve error |
| E20 | Central heating negative thermistor coefficient (NTC) sensor error |
| E28 | Flue negative thermistor coefficient (NTC) sensor error |
| E40 | Central heating return sensor error |
| E83 | Communication error |
| E109 | Pre-circulation fault |
| E110 | Safety thermostat operated |
| E118 | Primary system water pressure too low |
| E125 | Circulation error |
| E128 | Flame error |
| E130 | Flue negative thermistor coefficient (NTC) sensor operated |
| E133 | Interruption of gas supply or flame error |
| E135 | Interruption of gas supply |
| E154 | Flow return sensor temperature test |
| E160 | Fan or fan wiring error |
| E270 | Circulation fault (dry fire) |
| E321 | Hot water negative thermistor coefficient (NTC) error |
| E384 | False flame |
