Viessmann Boiler Fault Codes: A Comprehensive List and Common Issues
Viessmann boiler fault codes serve as a valuable tool for skilled technicians to detect and troubleshoot issues with Viessmann boilers. These codes utilise a combination of letters and numbers to pinpoint specific problems within the system, such as overheating, malfunctioning pumps, or low water pressure.
This article will provide a comprehensive list of Viessmann boiler codes and delve into one or two common fault codes in greater detail. By familiarising yourself with these codes, you can quickly identify and resolve any issues with your Viessmann boiler, ensuring optimal performance and longevity.
Company Overview
Viessmann is a leading manufacturer of high-efficiency boilers and heating products globally. The company prides itself on providing reliable and sustainable heating solutions for commercial and residential applications. Viessmann has a wide range of boilers, including gas-fired condensing and oil-fired boilers, designed to be energy-efficient while meeting the highest emissions standards.
In addition, Viessmann offers an array of smart controls to provide users with easy management of their heating systems while minimising energy consumption, reducing fuel costs, and promoting environmental sustainability. Combining modern technologies such as digital communications with traditional engineering techniques, Viessman’s innovative solutions have gained recognition from professionals worldwide as the ideal choice for customers looking for top-quality equipment with lower operational costs.
List of Viessman boiler fault codes, problems, and the reasons behind them
Vitoden 200 Boiler Error Codes
Fault Code | Problem | Reason |
---|
02 | Burner control switches to lockout | Safety chain was activated |
04, 05, 06, 08 | Burner control switches to lockout | Fan speed too high/low at start |
07, 09 | Burner control switches to lockout | Basic level of air pressure threshold in standby mode does not correct |
0D | Burner control switches to lockout | Reset button pressed repeatedly or while burner is running |
1A, 1B | Burner blocked | Flow sensor 1, 2 faulty |
1F | Burner blocked | Differential flow rate too large |
25 | Boiler operates with high boiler water temperature | Emissions test switch turned to “hand symbol” for 30 minutes already |
26 | Boiler operates with continuous relay test | Setting mode for maximum or minimum rated input active for 30 minutes already |
35 | Boiler does not activate | Reset button (pressed while burner is OFF) with emissions test switch turned to “hand symbol” |
A2 | N/A | KM-BUS fault to Vitocom |
A5 | N/A | Short circuit / open circuit |
Viessmann Fault Code 0B
Model | Problem | Reason |
---|
Vitodens 200 | Burner control switches to lockout. Fan does not idle after auto reset (incorrect fan rpm). | Severe wind conditions in vent system. |
Vitodens 100-W | Burner blocked | Insufficient water flow, incorrect flow direction, defective flow switch. |
Viessmann Fault Code 0C
Model | Problem | Reason |
---|
Vitodens 100-W | Burner blocked | Insufficient power supply |
Vitodens 200 | Burner control switches to lockout | Flame signal still present after switching off |
Viessmann Fault Code 0F
Model | Problem | Reason |
---|
Vitodens 222-F | Control mode | Code “0F” is only displayed in the fault history |
Vitotronic 300 / Vitotronic 300-K, with Vitotronic 300 / Vitodens 200-W / Vitocontrol-S, with Vitotronic 100 | Control mode / Controlled operation | Boiler service required |
Vitotronic 200 / 300 | Normal operation | Boiler service required |
Vitocontrol-S, MW1 with Vitotronic 100 / Vitotronic 300-K, MW1S with Vitotronic 100 | Control mode | Maintenance – “0F” is only displayed in the fault history |
Viessmann Fault Code 10
Model | Problem | Reason |
---|
Vitodens 200-W / 222-F / Vitotronic 300 / 200/ 200-H / 050/200-H / 300-K / Vitocontrol-S | Boiler operates based on outdoor temperature of 32°F / 0°C | Short circuit – outdoor temperature sensor |
Vitotronic 300-K, MW2S with Vitotronic 100 / Vitodens 100-W (combiPLUS) / 200-w / Vitocontrol-S, WB2B with Vitotronic 100 | Controls as if the outdoor temperature / Constant Mode | Outdoor temperature sensor shorted out |
Viessmann Error Code 10, 14, F3, and F4
Model | Problem | Reason |
---|
Vitodens 200-W / 222-F / Vitotronic 300 / 200 / 200-H / 050/200-H / 300-K / Vitocontrol-S | Boiler operates based on outdoor temperature of 32°F | Short circuit – outdoor temperature sensor |
Vitotronic 300-K, MW2S with Vitotronic 100 / Vitodens 100-W (combiPLUS) / 200-w / Vitocontrol-S, WB2B with Vitotronic 100 | Control as if the outdoor temperature is in constant mode | Outdoor temperature sensor shorted out |
Viessmann Fault Code 18 and D1
Model | Problem | Reason |
---|
Vitodens 100 / 200-W / 222-F / Vitotronic 300-K With 100 / Vitocontrol-S | Boiler operates based on outdoor temperature of 32°F / 0°C / Constant Mode | Outdoor temperature sensor cable broken |
Vitotronic / 100 / 200 / 300 / 050/200-H / 300-K / Vitocontrol-S, MW1 with Vitotronic 100 | Operates on basis of 32°F / 0°C outdoor temperature | Open circuit – Outdoor temperature sensor |
Vitotronic 200-H / Vitotronic 300-K, MW1B with Vitotronic 300 / Vitotronic 300-K, MW2B with Vitotronic 200 | Controls as if the outdoor temperature | Lead break – Outdoor temperature sensor |
Vitotronic 050/200-H | Activates after 0°C / 32°F outdoor temperature | Cable break – Outdoor temperature sensor |
Vitodens 100-W | Burner in fault mode | DIP switch S2 is set to “ON” |
Viessmann Fault Code 19
Model | Problem | Reason |
---|
Vitotronic 300 | Activates after 0°C / 32°F outdoor temperature | Communication fault, wireless outdoor temperature sensor |
Viessmann Fault Code 20
Model | Problem | Reason |
---|
Vitocontrol-S with Vitotronic 100 / Vitotronic 300 / 300-K / 200 / 100 | Stand-alone control unit without supply temperature sensor (possibly supply temperature not high enough) | Short circuit – Common supply temperature sensor |
Vitocontrol-S with Vitotronic 100 / Vitotronic 300-K, with Vitotronic 200 | Vitocontrol-S, controls in a stand-alone manner w/o supply temperature sensor (supply temperature may not be high enough) | Common supply temperature sensor shorted out |
Vitocrossal 300 | Regulates without supply temperature sensor (low-loss header) | Short circuit – System Flow temperature sensor |
Vitodens 200-W / 222-F | Regulates without supply temperature sensor (low-loss header) | Short circuit – System supply temperature sensor |
Vitotronic 050/200-H / 200 / 200-H / 300 | Mixing valve closed | Short circuit – Supply temperature sensor / mixing valve circuit M1 |
Vitotronic 300-K, with Vitotronic 100 | Vitotronic 300-K, MW1S controls in a stand-alone manner w/o strap-on sensor (supply temperature may not be high enough) | Short circuit – Strap-on temperature sensor |
Vitodens 200-W | Regulates without supply temperature sensor (low-loss header) | System supply temperature sensor shorted out |
Viessmann Fault Code 21
Model | Problem | Reason |
---|
Vitotronic 200 / 300 | Operation without influence of return water temperature | Short circuit – Return water temperature sensor |
Viessmann Error Code 28
Model | Problem | Reason |
---|
Vitocontrol-S with Vitotronic 100 | Vitocontrol-S, VD2/CT3/CM2 controls in a stand-alone manner w/o supply temperature sensor (supply temperature may not be high enough) | Open circuit – common supply temperature sensor |
Vitocontrol-S with Vitotronic 100 / Vitotronic 300-K, with Vitotronic 100 | Vitocontrol-S, WB2B controls in a stand-alone manner w/o supply temperature sensor (supply temperature might not be high enough) | Common supply temperature sensor cable broken |
Vitocrossal 300 / Vitodens 200-W / 22-F | Regulates without supply temperature sensor (low-loss header) | System supply temperature sensor cable broken |
Vitotronic 050/200-H | Mixing valve closes | Cable break – Supply temperature sensor |
Vitotronic 050/200-H | Mixing valve is closed | Open circuit – Supply temperature sensor of mixing valve circuit M1 |
Vitotronic 200-H / Vitotronic 200 / 300 | Mixing valve is being closed | Lead break – Supply temperature sensor in heating circuit with mixing valve M1 (heating circuit 1) |
Vitotronic 300 Vitotronic / 300-K with Vitotronic 300 / 200 | Stand-alone control unit without supply temperature sensor (possibly supply temperature not high enough) | Lead break, common supply temperature sensor |
Vitotronic 300-K with Vitotronic 100 | Vitotronic 300-K, MW1S controls in a stand-alone manner w/o strap-on sensor (supply temperature may not be high enough) | Open circuit – Strap-on temperature sensor |
Viessmann Fault Code 29, 41, 49, F80, F81, F83, F88 and F89
Model | Problem | Reason |
---|
Vitotronic 200 / 300 | Normal operation without influence of return water temperature | Open circuit 1 or 2 – Return water temperature sensor (of mixing valve circuit 1) |
Viessmann Fault Code 30
Model | Problem | Reason |
---|
Vitocontrol-S, with Vitotronic 100 / Vitocrossal 300 / Vitodens 200-W / 222-F / Vitotronic 100 / 200 / 300 | Adjustable high limit burner is started and stopped | Short circuit – Boiler water temperature sensor |
Vitocontrol-S with Vitotronic 100 / Vitodens 100-W (CombiPLUS)/ 200-1 | Burner blocked | Boiler water temperature sensor shorted out |
Viessmann Fault Code 38
Model | Problem | Reason |
---|
Vitodens – 200-W / 222-F / COMBIPLUS | Burner blocked | Boiler water temperature sensor cable broken |
Vitotronic 100 / 200 / 300 / Vitocontrol-S with Vitotronic 100 | Burner is switched on and off by the adjustable high limit | Open circuit – Boiler temperature sensor |
Vitotronic 300-K with Vitotronic 300 / Vitotronic 300-K with Vitotronic 300 | The burner is started and stopped via a temperature controller | Lead break, boiler water temperature sensor |
Vitodens 100-W | Burner blocked | Boiler water temperature sensor lead broken |
Viessmann Error Code 40 and 44
Model | Problem | Reason |
---|
All Viessmann boilers | Mixing valve closed | Heating circuit 2 with mixing valve supply short circuit on temperature sensor |
Viessmann Fault Code 41
Model | Problem | Reason |
---|
Vitotronic 300 | Operation without accounting for return water temperature | Short circuit – Return water temperature sensor of mixing valve circuit 2 |
Viessmann Fault Code 48 and 4C
Model | Problem | Reason |
---|
All Viessmann boilers | Mixing valve closes / closed | Heating circuit 2 with mixing valve supply temperature sensor cable broken / open circuit |
Viessmann Fault Code 50, 51, 58 and 59
Model | Problem | Reason |
---|
Vitodens 200-W / 222-F | No DHW heating / Fault with DHW | Short circuit/open circuit – DHW tank temperature sensor or lead break |
Viessmann Error Code 52
Model | Problem | Reason |
---|
Vitotronic 300 | Control mode | Short circuit – Supply temperature sensor low-loss header |
Vitodens 100-W CombiPLUS | Burner blocked (with CombiPLUS only) | Flow sensor shorted out (in CombiPLUS) |
Viessmann Fault Codes 55, 56, and 57
Model | Problem | Reason |
---|
Vitotronic 300-K, with Vitotronic 200 | Control mode | Maintenance or error on Vitotronic 100 of boiler 5-8 |
Viessmann Fault Codes 5A, B7, and B8
Model | Problem | Reason |
---|
All Viessmann boilers | Control mode | Lead break, low-loss header – Supply temperature sensor |
All Viessmann boilers | Burner blocked / control mode | Sensor cable broken |
Viessmann Error Codes 5C, 5D, 5E, and 5F
Model | Problem | Reason |
---|
Vitotronic 300-K with Vitotronic 200 | Control mode | Communication fault, Vitotronic 100 of boiler 5-8 |
Viessmann Fault Codes 60, 68, 70, 78, BD, BE, and BF
Model | Problem | Reason |
---|
All Viessmann boilers | No output reduction | Return control open, boiler with maximum temperature and Short/open circuit – Temperature sensor [17A] |
Viessmann Fault Codes FD, 80, 81, 82, and 83
Model | Problem | Reason |
---|
All Viessmann boilers | Burner control unit in a fault state; system cools down; burner control unit locked out | Short circuit – Boiler water temperature sensor, burner control unit |
Viessmann Error Codes 88, 89, and E6
Model | Problem | Reason |
---|
Vitocontrol-S with Vitotronic 100 / Vitotronic 300-K with Vitotronic 100 / 200 | Control mode | Communication error |
Viessmann Fault Codes 8C, 8D, 8E, and 8F
Model | Problem | Reason |
---|
Vitotronic 300 | Burner control unit in an error mode | Lead break, boiler water temperature sensor, burner control unit |
Viessmann Fault Codes 90, 91, 92, 93, 94, 98, 99, 9A, 9B, 9C, 9E, 9F, and AB
Model | Problem | Reason |
---|
Viessmann boilers | Control mode | Short circuit – Temperature sensor [5] / [6] / [7] / [10] |
Viessmann Error Codes A0, A1, A2, AA, and AC
Model | Problem | Reason |
---|
Vitodens 200 | Pump running at maximum speed | Open circuit – Internal BUS connection issue |
Viessmann Fault Codes F1, A3, B0, FE1, and FE2
Model | Problem | Reason |
---|
Vitocrossal 300 / Vitodens 200-W / 222-F / 300 | Control mode is in factory default setting | Programming unit is faulty |
Viessmann Fault Code A4
Model | Problem | Reason |
---|
Vitodens 222-F | Burner blocked. The venting program automatically starts. | Airlock in the internal circulation pump or minimum flow rate not achieved |
Viessmann Fault Code A7
Model | Problem | Reason |
---|
Vitocontrol-S with Vitotronic 100 / Vitotronic 100 / Vitotronic 300-K with Vitotronic 300 | Control mode (stays in factory default setting) | Isolation valve error coding OC:2, OC:3, or OC:4 set, and coding 4E:1 not set |
Viessmann Error Code A8
Model | Problem | Reason |
---|
All Boilers | Control mode issue | Programming unit communication fault |
Viessmann Fault Codes A9, BA, BB, BC, and FE0
Model | Problem | Reason |
---|
Vitodens 200 | Boiler cools down | Sensor inputs are not read correctly |
Viessmann Fault Code ADModel | Problem | Reason |
---|
Vitodens 200 | Setting via service level not possible | Data points are not stored internal error VR20 |
Viessmann Fault Code B1
Model | Problem | Reason |
---|
Vitocontrol-S with Vitotronic 100 / Vitotronic 100 / 200 / 300 / Vitotronic 300-K with Vitotronic 100 | Test mode on emissions | Internal electronics error |
Vitocontrol-S with Vitotronic 100 / Vitodens 200-W | Regulates as if the outside temperature was 32°F | Internal error |
Vitotronic 050/200-H | Control characteristics undefined | Electronics internal error |
Viessmann Error Code B2
Model | Problem | Reason |
---|
All Viessmann boilers | Control mode | Internal electronics error |
Viessmann Fault Codes B3 and E5Model | Problem | Reason |
---|
All boilers | Constant Mode | Invalid hardware recognized |
Viessmann Fault Code B4
Model | Problem | Reason |
---|
Vitocontrol-S with Vitotronic 100 / Vitotronic 100 / 200 / 300 / Vitotronic 300-K with Vitotronic 100 | Emissions test mode | Internal electronics fault |
Vitocontrol-S with Vitotronic 100 / Vitodens 200-W | Regulates as if the outside temperature was 32°F (0°C) | Internal fault |
Vitotronic 050/200-H | Undefined control characteristics | Internal electronics fault |
Viessmann Fault Code B6
Model | Problem | Reason |
---|
All Viessmann boilers | Control mode | Open circuit – KM bus to solar control unit communication error |
Viessmann Fault Codes B9, ED, F0, FE5, FEC, FED, FEE, FEF, FFD, and FFF
Model | Problem | Reason |
---|
Vitocontrol-S with Vitotronic 100 / Vitotronic 100 / 300 / Vitotronic 300-K with Vitotronic 300 | Boiler cools down | Error maximum pressure limiter 1 2 |
Viessmann Fault Code C1
Model | Problem | Reason |
---|
All Viessmann boilers | Burner control unit switches to lockout, this could be due to large line voltage fluctuations | Differential air pressure sensor open circuit |
Viessmann Fault Codes C2-C8, CD-CF, D2-D8, DA-DF, and E0
Model | Problem | Reason |
---|
All Viessmann boilers | Boiler cools down | Fixed high limit has responded or fuse F2 has blown. |
Viessmann Error code C9, CA, and CB
Model | Problem | Reason |
---|
All Viessmann boilers | Boiler drives up to electronic maximum limit | Boiler does not log in at the cascade control unit |
Viessmann Error code CC and F0
Model | Problem | Reason |
---|
All Viessmann boilers | Burner control unit is in fault mode | Ionisation current too high during calibration – Boiler temperature limiter responded air or blockage in system/pump error |
Viessmann Fault Code D4
Model | Problem | Reason |
---|
Vitotronic 300 / Vitotronic 300-K with Vitotronic 300 | Boiler cools down | Error with safety equipment at ‘X2/X3/X7’ of plug-in adaptor 2 for external safety equipment |
Vitodens 200 | Boiler is operating in emergency mode (after 30 mins BUS error) or boiler cools down | Internal bus error or open circuit internal bus connection |
Viessmann Fault Code D5
Model | Problem | Reason |
---|
All Viessmann boilers | Burner blocked | Flue gas temperature sensor not properly positioned – Check Sensor External pump fitted on system |
Viessmann Fault Codes FF, E1, E7, E8, E9, EA, EB, EC, and FF2
Model | Problem | Reason |
---|
Vitodens 200-W / 222-F / Vitotronic 300 | Burner in fault mode | Flow rate for heating hot water is too low during calibration / flow switch caused shutdown |
Viessmann Error Code E2 and E3
Model | Problem | Reason |
---|
All boilers | Burner in fault mode | Heating water flow rate too low during calibration; flow switch caused shutdown |
Viessmann Fault Code E4
Model | Problem | Reason |
---|
Vitotronic 300, Vitodens 200-W, 222-F, Vitocrossal 300, Vitocontrol-S with Vitotronic 100 | Burner error | Burner starts flame signal is too weak or missing |
Viessmann Fault Codes EE and EF
Model | Problem | Reason |
---|
Vitocontrol-S with Vitotronic 100 / Vitocrossal 300 / Vitodens 200-W / 222-F / Vitotronic 300 | Burner blocked | Faulty air pressure – switch air damper flap is stuck |
Viessmann Fault Code F5
Model | Problem | Reason |
---|
All Viessmann boilers | Gas pressure switch shows no gas pressure / electrical connection error | Gas shut-off valve closed / gas pressure switch faulty / multiple problems with gas supply |
Viessmann Fault Codes F6, 58, F9, FE1, FE2, and FF6
Model | Problem | Reason |
---|
All Viessmann boilers | Burner in error mode emergency operation | Fan not at standstill / plug-in connection error |
Viessmann Fault Codes FA and FB
Model | Problem | Reason |
---|
All Viessmann boilers | Control mode | Communication Fault with boiler |
Viessmann Error Codes FB7, FF4, FF2, FF7, FF8, and FF9
Model | Problem | Reason |
---|
Vitocrossal 200 | Case A: Burner control unit in a fault state; system cools down; burner control unit locked out.
Case B: Type of coding card. | Case A: Coding card not inserted in the burner control unit; incorrect or faulty coding card.
Case B: Coding card does not match burner control unit. |
Viessmann Fault Code FC
Model | Problem | Reason |
---|
All Viessmann boilers | Burner in fault mode | Gas valve faulty or faulty modulation valve control; or vent system blocked |
Viessmann Error Code FE
Model | Problem | Reason |
---|
All Viessmann boilers | Burner blocked or in error mode | Strong interference (EMC) field nearby, or faulty main PCB |
Viessmann Error Code FE4
Model | Problem | Reason |
---|
Vitocrossal 200 | Burner shuts down | Multiple detection of undervoltage |
Viessmann Fault Codes FFA, FFB, and FR
Model | Problem | Reason |
---|
Vitocrossal 200 / 400-620 / 186-311 | Fan runs without demand; burner control unit in a fault state | Fan has not stopped; cable [100A] faulty; fan faulty; burner control unit faulty |
Viessmann Error Code F4 EE
Model | Problem | Reason |
---|
Viessmann | Condensate pipe has frozen | As the condensate pipe lies outside the house it can get freeze. You can thaw it yourself but contacting a gas safe engineer would be a more viable option. |
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The 2 Most Common Viessman Boiler Fault Codes
After compiling a list of error and fault codes for Viessman boilers, it is important to address the two most prevalent issues troubling homeowners in the UK. These two common errors are the F2 fault code and the F4 fault code. To better understand these issues, let us delve into their details.
1. Viessman F2 fault code
The Viessmann boiler F2 fault code indicates a sudden interruption or lack of flame during the heating cycle. This type of issue could occur for various reasons, including gas valve issues, blocked flues, or dirty burner rods. The boiler system shuts down immediately as a safety precaution once this error occurs. Therefore, it requires immediate attention from a professional technician to accurately diagnose and fix the underlying cause of the problem.
Common Reasons behind the F2 fault code
There are three primary reasons for the f2 fault in Viessman boilers. Firstly, the condensate pipe can freeze during the cold winter because it is outside. This can disrupt the heating system. Secondly, heating sludge can also be a problem, as it can obstruct the heat flow in your home. Finally, airlocks and the loss of heating flame can also contribute to the F2 fault. It is important to address these issues promptly to ensure the proper functioning of your boiler.
How to fix F2 fault code
If the F2 fault code is occurring due to a frozen condensate pipe only, then the problem can be solved by unfreezing the pipe. If the fault is occurring due to other issues related to internal components, then you will have to contact a Gas Safe Engineer.
2. Viessman F4 fault code
The Viessmann F4 fault code is a commonly occurring issue in many heating systems. This code typically indicates a flame detection error, which means the unit is having trouble sensing the presence of a flame. There can be several reasons for this problem, including dirty or damaged electrodes, blocked burners or heat exchangers, faulty sensors or wiring, and gas supply or regulator issues.
It’s essential to address this issue immediately, as it could lead to safety hazards such as gas leaks and carbon monoxide buildup.
Common Reason behind the F4 fault code
Several common issues can cause the F4 fault code in Viessman boilers. One of the most frequent culprits is gas valves becoming stuck, which can prevent the boiler from igniting. Another potential problem is related to wiring or connection issues. Faulty or impaired flame sensors can also trigger the F4 error code.
Additionally, debris can block burner jets, preventing the boiler from igniting and leading to an F4 error. If none of these issues are the cause, the problem may lie with the PCB. In this case, it is best to have an engineer inspect the boiler and determine if the PCB needs to be replaced.
How to fix the F4 fault code
If you encounter an F4 fault code in your Viessmann boiler, you must seek the assistance of a Gas Safe Engineer. This issue indicates internal damage, which requires the expertise of a professional to address.
Fixing it yourself may result in further complications and potentially hazardous situations. Therefore, it is highly recommended that you leave this task in the capable hands of a qualified engineer.
Conclusion
Upon reading this article, you will no longer be caught off guard by any error codes that may appear on your Viessman Boiler. We have provided a detailed explanation of each code, so you know when to contact a Gas Safe Engineer.
However, if your boiler is becoming increasingly faulty and has surpassed the 10- to 15-year mark, it may be time to consider purchasing a new boiler. Our team is here to assist you in finding the perfect boiler to meet your needs.
Additionally, if budget constraints are a concern, we may be able to offer financing options. Don’t hesitate to contact us today for expert guidance and support.
Get a new boiler
today!
Get your new boiler and save your heating bill yearly with new energy efficient boiler.
Get a Quote Now