BoilerFaultCodes.com

Vaillant ecoMAX Fault Codes

CombiSystem Natural GasLPG 13-35 kW 2001-2006 Discontinued
GC Numbers: 47-044-1147-044-1247-044-1347-044-2447-044-2541-044-2841-044-2941-044-30

Replaced by: ecoTEC plus

The fault code is already on your display

Note it down before pressing reset — resetting clears the code immediately. How to read fault codes →

Most common fault codes

F.00
Your boiler has lost its connection to the sensor that monitors the temperature of the water leaving the unit, usually causing the system to stop working for safety.
Gas Safe engineer required · £90-180
F.0
Your boiler has lost its connection to the sensor that monitors the temperature of the water leaving the unit, causing it to shut down for safety.
Gas Safe engineer required · £90-160
F.01
Your boiler has lost connection with the sensor that monitors the water returning to the unit, causing it to shut down for safety.
Gas Safe engineer required · £90-160

All 28 fault codes

Code Severity Plain English
F.00 High Your boiler has lost its connection to the sensor that monitors the temperature of the water leaving the unit, usually causing the system to stop working for safety.
F.0 High Your boiler has lost its connection to the sensor that monitors the temperature of the water leaving the unit, causing it to shut down for safety.
F.01 High Your boiler has lost connection with the sensor that monitors the water returning to the unit, causing it to shut down for safety.
F.1 High Your boiler has detected a problem with the temperature sensor that monitors the water returning from your radiators, causing it to stop heating for safety.
F.10 High Your boiler has stopped working because it has detected an electrical fault with the internal sensor that monitors the temperature of the water leaving the unit.
F.11 High Your boiler has detected an electrical fault with the sensor that monitors water returning from your radiators, causing the system to shut down for safety.
F.13 Medium Your boiler has lost its connection to the hot water tank sensor, meaning it cannot tell how hot your water is and may stop providing it.
F.20 High Your boiler has switched itself off because it has detected that the internal temperature has become too hot and reached a dangerous level.
F.22 High Your boiler has detected that there is not enough water pressure inside the system to operate safely, causing it to shut down to prevent overheating.
F.23 High Your boiler has stopped working because the water isn't circulating properly between the pipes, causing a sudden and unsafe temperature gap.
F.24 High Your boiler is heating up much too fast because there isn't enough water moving through the system to carry the heat away.
F.25 High Your boiler has detected that the water pressure is too low or a safety switch has disconnected, causing the system to shut down for protection.
F.27 High Your boiler has detected a flame when there shouldn't be one, which means the safety system has locked the unit down to prevent an unsafe situation.
F.28 High Your boiler has tried to light several times but has been unable to establish a flame, meaning you have no heating or hot water.
F.29 High Your boiler was working but the flame has unexpectedly gone out, causing the system to shut down for safety.
F.32 High Your boiler’s air fan is not spinning at the correct speed to safely push exhaust fumes out of the flue, causing the system to shut down for safety.
F.49 High Your boiler's internal communication system is experiencing a power drop, meaning the main control board cannot talk to your thermostat or other smart controls.
F.60 High Your boiler has detected an electrical fault connected to the component that controls the gas flow, meaning it cannot safely light the burner.
F.61 High Your boiler is struggling to talk to the gas valve, which means it cannot safely light the flame to provide heating or hot water.
F.62 High Your boiler has detected that the gas valve is not closing as quickly as it should, preventing the unit from shutting down safely and causing it to lock out.
F.63 High Your boiler's internal computer brain has suffered a memory error and can no longer process the data it needs to run safely.
F.64 High Your boiler has detected a communication error between its internal sensors and the main control board, preventing it from heating your home safely.
F.65 High Your boiler's internal control board has become too hot to operate safely and has shut down to prevent damage.
F.67 High Your boiler's electronic control board is having trouble communicating with the flame sensor, meaning the system cannot safely confirm if the burner is lit.
F.70 High Your boiler's control board has lost its identity settings, meaning the internal computer no longer recognizes which model of boiler it is supposed to be controlling.
F.71 High Your boiler's temperature sensor is stuck on a single reading, meaning the system cannot safely tell if the water is heating up correctly.
F.72 High Your boiler is struggling to accurately measure water temperature because its sensors are sending conflicting or incorrect signals.
F.75 High Your boiler is unable to detect the necessary internal water pressure increase required to start the heating process.

Status & diagnostic codes

These codes indicate your boiler's operating state or a diagnostic reading — not necessarily a fault. Status codes (S.) mean normal operation; diagnostic codes (D.) are informational readings used by engineers.

Code Type Description
d.0 Diagnostic Your boiler is limiting its maximum output to match your heating needs, which is a normal setting adjustment rather than a breakdown.
d.1 Diagnostic Your boiler is briefly keeping the internal pump running after the heating has switched off to cool down the internal components.
d.2 Diagnostic Your boiler is currently taking a temporary break from heating after successfully reaching its target temperature to prevent it from turning on and off too frequently.
d.14 Diagnostic Your boiler is struggling to circulate water effectively because the internal pump is not running at the correct speed.
d.16 Diagnostic Your boiler is struggling to push heated water around your radiators because an external pump is not responding correctly.
d.71 Diagnostic Your boiler has reached its maximum allowed internal temperature limit for the heating system to protect the pipework and components.
d.72 Diagnostic Your boiler's pump is running longer than it should to cool down the system after heating water, usually because a sensor has detected a temperature imbalance.
d.73 Diagnostic Your boiler's pre-heat function for hot water isn't reaching the temperature it expects, which may lead to slower or inconsistent hot water delivery.

Vaillant ecoMAX is discontinued — time for a new one?

Parts for discontinued models can be hard to find and expensive. A new A-rated boiler could save you money on both repairs and energy bills.

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