Vaillant Ecotec Plus Fault codes & repairs

Welcome to our Vaillant Ecotect Plus fault codes & repairs page assist by AI as a guide only page, where the information given should be taken with a pinch of salt, however, with the AI assistant, it is recommended that any work undertaken is done by a qualified heating engineer and not meant for the average unqualifed person to try and fix there own boiler.

If you require assistance and would like to use our service, do feel free to contact the number on this page, and we can do everything to assist you in your time of need.

Not only do we give you a list of the vaillant ecotec plus fault codes and errors, we give you an idea to the issue that could be at cause.

In this article, not only do we give you a guide, the CEO of this company had drawn up a 3D model of the Vaillant ecotec plus for you to take a look at, which you can also visualise in AR using a capable device such as your phone.

Just below is a list of fault codes given the Vaillant Ecotec Plus codes and their problems.

Vaillant Ecotec Plus codes list

F00 - Interruption: Flow
F01 - Interruption: Return
F02 - Interruption: DHW outlet
F03 - Interruption: Cylinder Sensor
F10 - Short Circuit: Flow Sensor
F11 - Short circuit: Return sensor?
F12 - Short circuit: DHW outlet sensor
F13 - Short circuit: Cylinder sensor
F20 - Safety switch-off: Temperature limiter
F22 - Safety switch-off: Low water pressure
F23 - Safety switch-off: Temperature spread too large
F24 - Safety switch-off: Temperature increase too fast
F25 - Safety switch-off: Flue temperature too high
F26 - Fault: Fuel valve not working
F27 - Safety switch-off: Flame simulation
F28 - Start-up failure: Ignition unsuccessful
F29 - Operating failure: Ignition unsuccessful
F32 - Fault: Fan
F42 - Fault: Coding resistor
F49 - Fault: eBUS
F52 - Mass flow sensor not connected
F53 - Fault: Mass flow sensor
F54 - Fault: Boiler start
F55 - Fault: CO sensor
F56 - Safety switch-off: CO limit exceeded
F57 - Fault: Measuring program
F61 - Fault: Fuel valve actuation
F62 - Fault: Fuel valve switch off delay
F63 - Fault: EEPROM
F64 - Fault: Electronics/sensor
F65 - Fault: Electronics temp
F67 - Fault: Electronics/flame
F68 - Fault: Flame signal unstable
F70 - Fault: Invalid Device Specific Number
F71 - Fault: Flow sensor
F72 - Fault: Flow/return sensor
F73 - Fault: Water pressure sensor (signal too weak)
F74 - Fault: Water pressure sensor (signal too strong)
F75 - Fault: Pump/ water shortage
F77 - Fault: Flue non-return valve/condensate pump
F78 - Interrupt.: DHW outlet sensor on extemded controls
F80 - Fault: actoSTOR inlet sensor
F81 - Fault: cylinder charging pump
F82 - Fault: Extended current anode
F83 - Fault: NTC temperature gradient
F84 - Fault: NTC temperature difference implausible
F85 - Fault: NTCs fitted incorrectly
F90 - Fault: Communication
F91 - Fault: actoSTOR sensor
F92 - Fault: Incorrect gas type
F93 - Fault: Check gas route
F94 - Fault: Vortex and differential pressure
LED - actoSTOR Modul actoSTOR communication status
Communication fault

F00 - Interruption: Flow

An F.00 fault on a Vaillant ecotec plus gas boiler typically indicates a problem with the electronic control system.

This could be caused by a number of issues, such as a malfunctioning sensor, a software error, or a problem with the control module.

F01 - Interruption: Return

An F.01 fault on a Vaillant ecotec plus gas boiler typically indicates a problem with the flow sensor.

This could be caused by a blockage in the sensor, a malfunctioning sensor, or a problem with the wiring.

F02 - Interruption: DHW outlet

The F.02 fault code can be related to the Domestic Hot Water (DHW) outlet sensor or the cylinder temperature sensor.

These sensors are designed to monitor the temperature of the hot water being supplied to the DHW outlet or the temperature of the water inside the cylinder.

If the sensor is malfunctioning or the wiring is damaged, it can cause the F.02 fault code to be displayed on the boiler.

This can prevent further damage to the boiler and make sure that the heating system operates efficiently.

F03 - Interruption: Cylinder Sensor

The F.03 fault code on a Vaillant ecotec plus gas boiler can indicate a problem with the temperature sensor for the shift-load cylinder.

This sensor is used to measure the temperature of the water inside the cylinder, which is then used by the boiler's control module to adjust the heating system accordingly.

If the sensor is defective or not connected properly, it can cause the F.03 fault code to be displayed on the boiler.

It's important to have a qualified heating engineer diagnose the issue and fix it, this can prevent further damage to the boiler and make sure that the heating system operates efficiently.

F10 - Short Circuit: Flow Sensor

F10 is a fault code for a short circuit in the return sensor on a Vaillant ecotec plus boiler.

This sensor monitors the temperature of the water returning to the boiler, and if it detects a short circuit, it will shut down the boiler to prevent damage.

The return sensor may be faulty and needs to be replaced.

F11 - Short circuit: Return sensor

The F.11 fault code on a Vaillant ecotec plus gas boiler is related to a short circuit in the return temperature sensor.

This could be caused by a problem with the sensor itself, an issue with the wiring, or a problem with the boiler's control module.

F12 - Short circuit: DHW outlet sensor

F12 is a fault code for a short circuit in the domestic hot water (DHW) outlet on a Vaillant ecotec plus boiler.

This sensor monitors the temperature of the hot water leaving the boiler, and if it detects a short circuit, it will shut down the boiler to prevent damage.

The DHW outlet sensor may be faulty and needs to be replaced.

F13 - Short circuit: Cylinder sensor

F13 is a fault code for a short circuit in the cylinder sensor on a Vaillant ecotec plus boiler.

This sensor monitors the temperature of the water in the cylinder, and if it detects a short circuit, it will shut down the boiler to prevent damage.

The cylinder sensor may be faulty and needs to be replaced.

F20 - Safety switch-off: Temperature limiter

F20 is a fault code for a safety switch off, temperature limiter on a Vaillant ecotec plus boiler.

This means that the boiler has detected that the temperature has exceeded the limit set by the manufacturer and has shut down to prevent overheating and potential damage.

This may be due to a malfunction in the temperature control system, or it could be caused by a lack of maintenance or blockages in the system.

We have more on the F20 fault code in our Vaillant Boiler F20 Fault Code article.

F22 - Safety switch-off: Low water pressure

F22 is a fault code for a safety switch off, low water pressure on a Vaillant ecotec plus boiler.

This means that the boiler has detected that the water pressure in the system has dropped below the minimum level required for safe operation, and has shut down as a safety measure.

This can be caused by a leak in the system, a blockage, or a malfunction in the pressure regulating valve.

It can also be caused by low water pressure coming into the property.

We have more on the F22 fault code in our Vaillant Boiler F22 Fault Code article.

F23 - Safety switch-off: Temperature spread too large

F23 is a fault code for a safety switch off, temperature spread too large on a Vaillant ecotec plus boiler.

This means that the boiler has detected a large difference in temperature between the flow and return temperature sensors, indicating a problem in the heating system.

This could be caused by a malfunction in the boiler, a blockage in the system, or issues with the circulation of the water through the system.

We have more on the F23 fault code in our Vaillant Boiler F23 Fault Code article.

F24 - Safety switch-off: Temperature increase too fast

F24 is a fault code for a safety switch off, temperature spread too fast on a Vaillant ecotec plus boiler.

This means that the boiler has detected a rapid change in temperature between the flow and return temperature sensors, indicating a problem in the heating system.

This could be caused by a malfunction in the boiler, a blockage in the system, or issues with the circulation of the water through the system. It could also happen due to incorrect adjustment of the room thermostat, causing the boiler to shut down.

We have more on the F24 fault code in our Vaillant Boiler F24 Fault Code article.

F25 - Safety switch-off: Flue temperature too high

F25 is a fault code for a safety switch off, flue temperature too high on a Vaillant ecotec plus boiler.

This means that the boiler has detected that the flue gas temperature is higher than it should be and has shut down as a safety measure. This could be caused by a blocked flue, a malfunction in the boiler or a problem with the combustion process.

It could also be caused by a lack of fresh air supply to the boiler, causing incomplete combustion.

F26 - Fuel valve not working

F26 is a fault code for a fuel valve not working on a Vaillant ecotec plus boiler.

This means that the boiler is not able to open or close the fuel valve properly, preventing the boiler from operating.

This could be caused by a malfunction in the fuel valve, or a problem with the control circuit that operates the valve.

This fault code can also happen if the valve is stuck open or closed, preventing the normal combustion process.

F27 - Safety switch-off: Flame simulation

F27 is a fault code for a safety switch-off, flame simulation on a Vaillant ecotec plus boiler.

This means that the boiler has detected an issue with the flame sensor or the flame simulation circuit, and has shut down as a safety measure.

This could be caused by a malfunction in the flame sensor, a problem with the circuit that controls the flame, or a lack of fuel supply.

It could also happen if the boiler is not able to detect the flame properly, which can be caused by dirt or a buildup of debris on the flame sensor.

We have more on the F22 fault code in our Vaillant Boiler F22 Fault Code article.

F28 - Start-up failure: Ignition unsuccessful

F28 is a fault code for a start-up failure, ignition unsuccessful on a Vaillant ecotec plus boiler.

This means that the boiler has attempted to start and ignite the burner, but was unsuccessful.

This could be caused by a malfunction in the ignition system, a lack of fuel supply, or a problem with the control circuit that operates the ignition system.

It could also happen if the boiler is not able to detect the flame properly or if the flame sensor is not working, which can be caused by dirt or a buildup of debris on the flame sensor.

We have more on the F28 fault code in our Vaillant Boiler F28 Fault Code article.

F29 - Operating failure: Ignition unsuccessful

F29 is a fault code for an operating failure, ignition unsuccessful on a Vaillant ecotec plus boiler.

This means that the boiler has attempted to ignite the burner during normal operation, but was unsuccessful.

This could be caused by a malfunction in the ignition system, a lack of fuel supply, or a problem with the control circuit that operates the ignition system.

It could also happen if the boiler is not able to detect the flame properly or if the flame sensor is not working, which can be caused by dirt or a buildup of debris on the flame sensor.

It could also be caused by a lack of maintenance of the boiler, like clogged nozzles, faulty injectors or a malfunctioning combustion fan.

We have more on the F29 fault code in our Vaillant Boiler F29 Fault Code article.

F32 - Fan

The F32 fault code on a Vaillant Ecotec Plus boiler indicates a problem with the fan.

It could be caused by a number of issues such as a defective fan, faulty wiring, or a malfunctioning fan control board.

The fan is a crucial component of the boiler as it helps circulate heat and maintain the proper air/fuel ratio for combustion.

To resolve the issue, you may need to have the fan, wiring, or fan control board inspected and repaired.

We have more on the F32 fault code in our Vaillant Boiler F32 Fault Code article.

F42 - Fan

The F42 fault code on a Vaillant Ecotec Plus boiler indicates a problem with the pressure switch circuit.

The pressure switch is responsible for monitoring the pressure of the heating system and sending a signal to the boiler's control board if the pressure drops too low.

The resistance in the pressure switch circuit can affect the operation of the pressure switch, causing the F42 error code to be displayed.

To resolve the issue, you may need to have the pressure switch and its circuit inspected and repaired by a qualified heating engineer.

This could involve replacing the pressure switch or fixing any issues with the wiring or resistance in the circuit.

The gas group resistor can also cause a short circuit which could trigger the F42 fault code on a Vaillant Ecotec Plus boiler.

The gas group resistor is responsible for controlling the flow of gas to the burner, and a short circuit in the resistor can cause problems with the pressure switch circuit.

If the pressure switch circuit is not functioning properly, it may cause the F42 fault code to be displayed.

To resolve the issue, a qualified heating engineer will need to inspect the gas group resistor and the pressure switch circuit, and repair or replace any faulty components.

F49 - eBUS

The F49 fault code on a Vaillant Ecotec Plus boiler indicates an undervoltage on the eBUS (electronic bus system).

This means that the voltage supply to the boiler's control board is not sufficient for it to operate correctly.

The eBUS is responsible for communication between various components of the boiler and a problem with the voltage supply can affect its operation.

An undervoltage on the eBUS can be caused by a number of factors, including a faulty power supply, loose wiring, or a malfunctioning control board.

To resolve the issue, a qualified heating engineer will need to inspect the power supply, wiring, and control board, and repair or replace any faulty components.

F52 - Mass flow sensor not connected

The F52 fault code on a Vaillant Ecotec Plus boiler indicates a problem with the mass flow sensor.

The mass flow sensor is responsible for measuring the flow of gas to the burner and ensuring that the proper amount of gas is being supplied for combustion.

If the mass flow sensor is defective or not connected, it can cause problems with the operation of the boiler, leading to the F52 fault code being displayed.

To resolve the issue, a qualified heating engineer will need to inspect the mass flow sensor, check its connections, and repair or replace it if necessary.

If the mass flow sensor is not the cause of the problem, the heating engineer may need to inspect other components of the system to determine the source of the issue.

F53 - Fault: Mass flow sensor

The F53 fault code on a Vaillant Ecotec Plus boiler indicates a problem with the mass flow sensor.

The mass flow sensor is responsible for measuring the flow of gas to the burner and ensuring that the proper amount of gas is being supplied for combustion.

If the mass flow sensor is defective, it can cause problems with the operation of the boiler, leading to the F53 fault code being displayed.

To resolve the issue, a qualified heating engineer will need to inspect the mass flow sensor and repair or replace it if necessary.

If the mass flow sensor is not the cause of the problem, the heating engineer may need to inspect other components of the system to determine the source of the issue.

F54 - Boiler start

The F54 fault code on a Vaillant Ecotec Plus boiler indicates a problem with the gas inlet pressure.

The gas inlet pressure is the pressure at which gas is supplied to the boiler and is critical for proper operation.

If there is no gas inlet pressure or if the pressure is insufficient, it can cause problems when starting the boiler and lead to the F54 fault code being displayed.

This can be caused by a number of factors, including a blockage in the gas supply line, a faulty gas valve, or a malfunctioning pressure regulator.

To resolve the issue, a qualified heating engineer will need to inspect the gas supply, valve, and pressure regulator, and repair or replace any faulty components.

F55 - CO sensor

The F55 fault code on a Vaillant Ecotec Plus boiler indicates a problem with the gas sensor.

The gas sensor is responsible for detecting the presence of gas and ensuring that the proper amount of gas is being supplied for combustion.

If the gas sensor is defective or has short-circuited, it can cause problems with the operation of the boiler, leading to the F55 fault code being displayed.

To resolve the issue, a qualified heating engineer will need to inspect the gas sensor and repair or replace it if necessary.

If the gas sensor is not the cause of the problem, the heating engineer may need to inspect other components of the system to determine the source of the issue.

F56 - Safety switch-off: CO limit exceeded

The F56 fault code on a Vaillant Ecotec Plus boiler indicates that the safety shutdown has been triggered due to the CO (carbon monoxide) limit value being exceeded.

The CO limit value is a safety measure that is designed to protect against the build-up of dangerous levels of carbon monoxide, which can be deadly if inhaled.

If the CO limit value is exceeded, the boiler will automatically shut down as a safety precaution.

This can be caused by a number of factors, including poor combustion, a blockage in the flue or chimney, or a malfunctioning gas sensor.

To resolve the issue, a qualified heating engineer will need to inspect the boiler and its components, repair or replace any faulty components, and ensure that the combustion process is functioning properly.

It is important to address this issue promptly and take the necessary safety precautions to ensure that your home and family are protected from the dangers of carbon monoxide.

F57 - Measuring program

The F57 fault code on a Vaillant Ecotec Plus boiler indicates a problem with the regulation.

This could be caused by a corroded ignition electrode, which is responsible for igniting the gas and starting the combustion process.

If the electrode is corroded, it can interfere with the proper functioning of the regulation system, leading to the F57 fault code being displayed.

To resolve the issue, a qualified heating engineer will need to inspect the electrode, clean or replace it if necessary, and ensure that the regulation system is functioning properly.

If the electrode is not the cause of the problem, the heating engineer may need to inspect other components of the system to determine the source of the issue.

F61 - Fuel valve actuation

The F61 fault code on a Vaillant Ecotec Plus boiler indicates a problem with the gas valve assembly.

The gas valve assembly is responsible for controlling the flow of gas to the burner and is critical for proper operation of the boiler.

If the gas valve assembly cannot be actuated, it can cause problems with the operation of the boiler, leading to the F61 fault code being displayed.

This can be caused by a number of factors, including a malfunctioning gas valve, a blockage in the gas supply line, or a problem with the wiring or control board.

To resolve the issue, a qualified heating engineer will need to inspect the gas valve assembly, gas supply line, and control board, and repair or replace any faulty components.

If the gas valve assembly is not the cause of the problem, the heating engineer may need to inspect other components of the system to determine the source of the issue.

We have more on the F61 fault code in our Vaillant Boiler F61 Fault Code article.

F62 - Fuel valve switch off delay

The F62 fault code on a Vaillant Ecotec Plus boiler indicates a problem with the delayed switch off sequence for the gas valve after the flame is extinguished.

This could be caused by a malfunction in the gas valve or the control board, leading to the gas valve not being turned off after the flame is extinguished.

This can cause the boiler to continue to use gas even though there is no flame, leading to the F62 fault code being displayed.

To resolve the issue, a qualified heating engineer will need to inspect the gas valve and control board, repair or replace any faulty components, and ensure that the delayed switch off sequence for the gas valve is functioning properly.

If the gas valve or control board is not the cause of the problem, the heating engineer may need to inspect other components of the system to determine the source of the issue.

We have more on the F62 fault code in our Vaillant Boiler F62 Fault Code article.

F63 - EEPROM

The F63 fault code on a Vaillant Ecotec Plus boiler indicates a problem with the EEPROM (Electrically Erasable Programmable Read-Only Memory).

The EEPROM is a type of memory chip that stores important information such as settings and fault codes.

If the EEPROM is faulty, it can cause problems with the operation of the boiler, leading to the F63 fault code being displayed.

This can be caused by a variety of factors, including a malfunctioning EEPROM chip, a power interruption, or a problem with the wiring or control board.

To resolve the issue, a qualified heating engineer will need to inspect the EEPROM chip, wiring, and control board, and repair or replace any faulty components.

If the EEPROM chip is not the cause of the problem, the heating engineer may need to inspect other components of the system to determine the source of the issue.

We have more on the F63 fault code in our Vaillant Boiler F63 Fault Code article.

F64 - Electronics/sensor

The F64 fault code on a Vaillant Ecotec Plus boiler indicates a problem with the electronics, safety-relevant sensor, or cable.

Safety-relevant sensors, such as the flame sensor or pressure sensor, are critical components of the boiler system and are responsible for monitoring the safe operation of the boiler.

If one of these sensors or their associated cables is defective, it can cause problems with the operation of the boiler, leading to the F64 fault code being displayed.

This can be caused by a variety of factors, including a malfunctioning sensor, a damaged cable, or a problem with the wiring or control board.

To resolve the issue, a qualified heating engineer will need to inspect the safety-relevant sensors and cables, wiring, and control board, and repair or replace any faulty components.

If the sensors or cables are not the cause of the problem, the heating engineer may need to inspect other components of the system to determine the source of the issue.

We have more on the F64 fault code in our Vaillant Boiler F64 Fault Code article.

F65 - Electronics temp

The F65 fault code on a Vaillant Ecotec Plus boiler indicates a problem with the electronics.

This can be caused by a variety of factors, including a malfunctioning control board, an overheating issue, or a problem with the wiring.

Overheating can be caused by external influences such as an obstruction blocking air flow around the boiler or a buildup of dust and debris on the heat exchanger.

If the electronics are defective or overheating, it can cause problems with the operation of the boiler, leading to the F65 fault code being displayed.

To resolve the issue, a qualified heating engineer will need to inspect the control board, wiring, and surrounding components, and repair or replace any faulty components.

If the control board is not the cause of the problem, the heating engineer may need to inspect other components of the system to determine the source of the issue.

We have more on the F65 fault code in our Vaillant Boiler F65 Fault Code article.

F67 - Electronics/flame

The F67 fault code on a Vaillant Ecotec Plus boiler indicates an "implausible flame signal."

This means that the boiler's control system has detected an issue with the flame sensor or flame detection circuit that is causing an abnormal flame signal.

The flame sensor is responsible for monitoring the presence and stability of the flame in the combustion chamber, and is a critical component for ensuring safe and efficient operation of the boiler.

If the flame sensor or its associated circuit is not functioning correctly, it can cause the F67 fault code to be displayed.

To resolve the issue, a qualified heating engineer will need to inspect the flame sensor and its associated wiring and components, and repair or replace any faulty parts.

If the flame sensor is not the cause of the problem, the heating engineer may need to inspect other components of the system to determine the source of the issue.

We have more on the F67 fault code in our Vaillant Boiler F67 Fault Code article.

F68 - Flame signal unstable

The F68 fault code on a Vaillant Ecotec Plus boiler indicates an "unstable flame signal." This means that the boiler's control system has detected an issue with the flame sensor or flame detection circuit, causing an abnormal flame signal.

An unstable flame signal can indicate that the flame is flickering or not burning correctly, which can be a serious safety concern.

To ensure safe and efficient operation of the boiler, the flame sensor must be functioning correctly.

If the F68 fault code is displayed, a qualified heating engineer will need to inspect the flame sensor and its associated wiring and components, and repair or replace any faulty parts.

If the flame sensor is not the cause of the problem, the heating engineer may need to inspect other components of the system to determine the source of the issue.

We have more on the F68 fault code in our Vaillant Boiler F68 Fault Code article.

F70 - Invalid Device Specific Number

The F70 fault code on a Vaillant Ecotec Plus boiler indicates an "incorrect/missing device specific number or incorrect/missing coding resistor."

This means that the boiler's control system has detected an issue with the identification data for one of the components in the system, such as the gas valve, fan, or burner, or with the coding resistor that provides information about the type of component that is installed.

The device specific number and coding resistor are used by the boiler's control system to identify the components and to ensure that the correct parameters are used for their operation.

If the F70 fault code is displayed, a qualified heating engineer will need to inspect the device specific number and coding resistor, and correct or replace any faulty parts.

This is important to ensure that the boiler operates correctly and safely.

We have more on the F70 fault code in our Vaillant Boiler F70 Fault Code article.

F71 - Flow senso

The F71 fault code on a Vaillant Ecotec Plus boiler indicates an "implausible flow temperature sensor value." This means that the boiler's control system has detected an issue with the flow temperature sensor, which measures the temperature of the water that is flowing through the heating system.

If the flow temperature sensor is returning implausible values, it may indicate a problem with the sensor itself or with its wiring and connections.

The flow temperature sensor is a critical component that provides important information to the boiler's control system, and it must be functioning correctly for the boiler to operate safely and efficiently.

If the F71 fault code is displayed, a qualified heating engineer will need to inspect the flow temperature sensor, and repair or replace any faulty parts.

This will ensure that the boiler operates correctly and safely.

We have more on the F71 fault code in our Vaillant Boiler F71 Fault Code article.

F72 - Flow/return sensor

The F72 fault code on a Vaillant Ecotec Plus boiler indicates a "high temperature difference between flow and return temperature sensor." This means that the difference in temperature readings between the flow temperature sensor and the return temperature sensor is outside of the acceptable range for the boiler.

The flow temperature sensor measures the temperature of the water that is flowing through the heating system, and the return temperature sensor measures the temperature of the water that is returning to the boiler.

If the temperature difference between these two sensors is too great, it may indicate a problem with the heating system, such as poor circulation or a blockage in the pipework.

In some cases, the F72 fault code may be caused by a failure of one of the temperature sensors, or by a problem with the wiring or connections between the sensors and the control system.

A qualified heating engineer will need to inspect the temperature sensors and their wiring, and repair or replace any faulty parts in order to resolve the issue and restore the proper functioning of the heating system.

This will ensure that the boiler operates correctly and safely.

We have more on the F72 fault code in our Vaillant Boiler F72 Fault Code article.

F73 - Water pressure sensor (signal too weak)

The F73 fault code on a Vaillant Ecotec Plus boiler indicates a "low water pressure" issue.

This means that the water pressure sensor is reporting that the pressure in the heating system is below the minimum required level.

This can be caused by a variety of issues, including a leak in the system, a blocked pump, or a malfunctioning pressure relief valve.

A low water pressure condition can impact the operation and efficiency of the heating system, and may cause damage to the boiler and other components.

It is important to address this issue as soon as possible by calling a qualified heating engineer.

The engineer will inspect the heating system, diagnose the cause of the low pressure, and repair or replace any faulty components as necessary to restore proper water pressure and ensure the safe and efficient operation of the boiler.

F74 - Water pressure sensor (signal too strong)

The F74 fault code on a Vaillant Ecotec Plus boiler indicates a "high water pressure" issue.

This means that the water pressure sensor is reporting that the pressure in the heating system is above the maximum allowed level.

This can be caused by a variety of issues, including an overfilled system, a malfunctioning pressure reducing valve, or a problem with the expansion vessel.

High water pressure can impact the operation and efficiency of the heating system, and may cause damage to the boiler and other components.

It is important to address this issue as soon as possible by calling a qualified heating engineer.

The engineer will inspect the heating system, diagnose the cause of the high pressure, and repair or replace any faulty components as necessary to restore proper water pressure and ensure the safe and efficient operation of the boiler.

We have more on the F73 & F74 fault code in our Vaillant Boiler F73 & F74 Fault Code article.

F75 - Pump/ water shortage

The F75 fault code on a Vaillant ecotec plus boiler indicates that there is an insufficient pressure increase (pressure jump) detected when starting the pump.

This could be due to a problem with the pump, or a restriction in the system that is preventing proper flow.

It is recommended to have a qualified heating engineer inspect the system to diagnose and resolve the issue.

We have more on the F75 fault code in our Vaillant Boiler F75 Fault Code article.

F77 - Flue non-return valve/condensate pump

The F77 fault code on a Vaillant ecotec plus boiler indicates a problem with the non-return flue flap or the condensate pump overflow.

The non-return flue flap provides feedback to the boiler to ensure proper flueing, and the condensate pump is responsible for removing any condensation that may form in the flue system.

A failure of either of these components could cause the F77 fault code to appear.

It is recommended to have a qualified heating engineer inspect the system to diagnose and resolve the issue.

F78 - DHW outlet sensor on extension controls

The F78 fault code on a Vaillant ecotec plus boiler indicates that the UK link box is connected to the boiler without the domestic hot water temperature sensor being bridged.

This means that the boiler is not able to receive information from the temperature sensor, which is needed to regulate the domestic hot water temperature.

The fault may need to be resolved by a qualified heating engineer to ensure safe and proper operation of the boiler.

F80 - actoSTOR inlet sensor

F80 fault code in a Vaillant ecotec plus boiler indicates that there is a problem with the inlet temperature sensor.

This could mean that the sensor is defective or not connected properly.

It could also indicate that the sensor is reading incorrect values.

This issue could affect the proper functioning of the boiler and it's recommended to have it inspected and repaired by a qualified technician.

F81 - cylinder charging pump

The F81 fault code on a Vaillant ecotec plus boiler indicates that the hot water cylinder is not fully charged after a specified amount of time.

This issue can be caused by various factors, such as a lack of water flow, a faulty hot water thermostat, a faulty pressure relief valve, a problem with the diverter valve or cylinder stat, or a fault with the pump.

To resolve this issue, it is recommended that you contact a qualified heating engineer to diagnose and repair the problem.

F82 - Extension current anode

The F82 fault code on a Vaillant ecotec plus boiler is related to the external current anode being defective or not connected.

This fault code indicates that there is a problem with the external current anode, which is a device used to protect the boiler against corrosion.

It may mean that the anode is not working properly, or that it is not connected properly to the boiler.

If you see this fault code, it is recommended that you contact a qualified heating engineer for repair and maintenance.

F83 - NTC temperature gradient

The F83 fault code on a Vaillant ecotec plus boiler indicates that the temperature difference between the flow and return temperature sensors is too small.

This could mean that there is a problem with the sensors or the way they are communicating with the boiler's control system.

The cause of the issue should be determined and repaired by a qualified heating engineer to ensure the safe and efficient operation of the boiler.

We have more on the F83 fault code in our Vaillant Boiler F83 Fault Code article.

F84 - NTC temperature difference implausible

The F84 fault code on a Vaillant ecotec plus boiler is related to the temperature difference being implausible.

This means that the difference between the flow and return temperature sensors is not within the expected range, indicating a possible malfunction of one of the sensors or the connection to them.

This can cause problems with the heating and hot water systems, so it's important to have it repaired by a qualified technician as soon as possible.

We have more on the F84 fault code in our Vaillant Boiler F84 Fault Code article.

F85 - NTCs fitted incorrectly

The F85 fault code on your Vaillant ecotec plus boiler indicates that the flow and return temperature sensors are returning incorrect or implausible values.

This could be caused by a number of issues including incorrect installation of the sensors, problems with the wiring, or issues with the sensors themselves.

To resolve the issue, a qualified heating engineer should be consulted to diagnose the specific cause and make the necessary repairs.

We have more on the F85 fault code in our Vaillant Boiler F85 Fault Code article.

F90 - Communication

The F90 fault code on a Vaillant ecotec plus boiler indicates a communication error between the boiler and the actoSTOR (a hot water storage tank).

This could mean that the actoSTOR is not communicating with the boiler or that there is a problem with the communication between the two components.

To resolve the issue, it may be necessary to reset the actoSTOR or check its connection to the boiler.

If the problem persists, it is recommended to seek the help of a qualified technician.

F91 - actoSTOR sensor

The F91 fault code on a Vaillant ecotec plus boiler indicates a problem with the sensor on the actoSTOR (a type of hot water storage tank).

This could mean that the sensor is defective, not connected properly, or not working as intended.

To resolve this issue, you may need to have a qualified technician inspect and repair or replace the sensor.

F92 - Incorrect gas type

The F92 fault code on a Vaillant ecotec plus boiler indicates that there is a mismatch between the coding resistor on the Printed Circuit Board (PCB) and the entered gas group.

This means that the boiler has been set up for use with a different type of gas than what is currently being used.

This can cause improper operation of the boiler and may pose a safety risk.

It is recommended to have a qualified heating technician resolve this issue.

F93 - Check gas route

The F93 fault code on a Vaillant ecotec plus boiler indicates that there is an issue with the combustion quality.

This fault code is related to the combustion process in the boiler, and it can be caused by several factors, including a malfunctioning gas valve, a faulty air pressure sensor, or a problem with the flame.

To resolve the issue, it may be necessary to have a professional heating technician perform a diagnostic and repair the boiler.

F94 - Vortex and differential pressure

The F94 fault code on a Vaillant ecotec plus boiler indicates that the sensors are returning values that are outside the expected range, which may mean that they are not working correctly or there is a problem with the system they are monitoring.

This can impact the performance of the boiler and could potentially cause safety issues, so it is important to have it addressed by a professional.

LED - actoSTOR Modul actoSTOR communication status communication fault

Why have I got an LED actoSTOR Modul actoSTOR communication status issue on my Vaillant ecotec plus boiler and is it related to theactoSTOR communication status: Not connected, Con- nection error, Connection active with the communication between the actoSTOR module and the boiler.

It could be related to a "Not connected" or "Connection error" status, indicating a problem with the physical connection between the two devices, or a "Connection active" status, indicating that the devices are connected but there is a communication error.

If you encounter this issue, it is recommended to contact a qualified heating engineer for assistance in diagnosing and resolving the problem.

Communication Fault

Why have I got a Communication fault on my Vaillant ecotec plus boiler and is it related to the Communication fault between the display and the PCB in the electronics box PCB, or a connection issue between the two.

It's best to have a heating engineer diagnose the issue and determine the cause of the problem.

If you want to experience a Vaillant Eco Tec but in AR, do feel free to check out out Vaillant Eco Tec AR page.

We have many more boiler problems in our boiler faults problems page, that is currently undergoing a revamp.