ECA Proteus Premix 24 HCH Fault codes & diagnostics

28 fault codes with plain-English explanations, severity ratings, DIY guidance, and repair cost estimates.

Regular Natural GasLPG 24 kW 2017-present
GC Number 41-814-01
Download the ECA Proteus Premix 24 HCH manualThe official installation and service manual (PDF), the document these fault codes were read from. PDF

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Severity at a glance

Each cell = one fault code. Hover to identify.
2 Emergency 19 High 5 Medium 2 Low

Which version do you have?

The GC number on your boiler's data badge identifies the exact appliance and production years, as recorded in the UK Product Characteristics Database.

GC number Appliance (register name) Produced
41-814-01 PROTEUS PREMIX 24 HCH NG ERP UK 2017–present

Appliance names and production years are taken from the UK Product Characteristics Database (the SAP/SEDBUK register). Where a GC number is also printed in this model's own manufacturer manual, both sources were checked to agree.

All 28 documented codes

Tap any card for details

E01

Your boiler has failed to light its burner and safely start up.

High Engineer only £150-350

Parts commonly replaced

  • Ignition electrode
  • Gas valve
  • Printed circuit board

Related codes

E02

Your boiler is temporarily locked out because it thinks it detects a flame burning inside before it has even tried to turn on.

Emergency Engineer only £100-£250

Parts commonly replaced

  • Flame sensor electrode
  • Printed circuit board (PCB)

Related codes

E03

Your boiler has temporarily shut down because the water inside it has become too hot, triggering a vital safety cutoff to prevent overheating.

High Engineer only £100-250

Parts commonly replaced

  • High limit thermostat
  • NTC temperature sensor
  • Circulating pump
  • PCB

Related codes

E05

Your boiler has stopped working because it cannot detect that the internal fan is spinning correctly to clear exhaust gases safely.

High Engineer only £150-300

Parts commonly replaced

  • Fan Assembly
  • Printed Circuit Board (PCB)

Related codes

E08

Your boiler has detected an issue with the flame during operation and safely shut itself down to prevent any hazards.

High Engineer only £150-300

Parts commonly replaced

  • Ignition Lead
  • Electrodes
  • Gas Valve
  • PCB

Related codes

E09

Your boiler is failing to register that the internal gas valve is operating correctly, meaning it will lock out for safety and stop providing heating and hot water.

High Engineer only £150-£300

Parts commonly replaced

  • Gas Valve
  • Wiring Harness
  • Printed Circuit Board (PCB)

Related codes

E12

Your boiler has detected a memory error within its main control board, meaning it cannot safely store or read its internal settings.

High Engineer only £150-300

Parts commonly replaced

  • Printed Circuit Board (PCB)

Related codes

E15

Your boiler has detected an inconsistent temperature reading between its internal sensors, meaning it cannot accurately monitor how hot the water is getting.

High Engineer only £120-£250

Parts commonly replaced

  • NTC Temperature Sensor
  • Central Heating Thermistor

Related codes

E16

Your boiler has temporarily stopped working because it cannot accurately read the temperature of the water heading into your heating system.

High Engineer only £90-£180

Parts commonly replaced

  • Central Heating NTC Temperature Sensor
  • Wiring harness

Related codes

E17

Your boiler has detected a problem with the sensor that measures the temperature of the water returning from your radiators.

High Engineer only £90-180

Parts commonly replaced

  • Central Heating Return Temperature Sensor
  • Wiring harness

Related codes

Showing 11–20 of 28
E18

Your boiler has temporarily stopped working because it cannot accurately read the temperature of the water inside.

High Engineer only £90-180

Parts commonly replaced

  • NTC Temperature Sensor
  • Wiring Harness

Related codes

E21

Your boiler's internal computer is experiencing a critical electronic failure and cannot properly process its internal signals.

High Engineer only £200-£400

Parts commonly replaced

  • Printed Circuit Board (PCB)
E33

Your boiler has temporarily stopped working because it cannot accurately read the temperature of the water returning from your radiators.

High Engineer only £90-180

Parts commonly replaced

  • Central Heating Return Temperature Sensor
  • Wiring Harness

Related codes

E35

Your boiler has temporarily stopped working because it cannot accurately read the temperature of the water flowing into your central heating system.

High Engineer only £90-180

Parts commonly replaced

  • Central Heating Flow Temperature Sensor
  • Wiring Harness

Related codes

E80

Your boiler is temporarily pausing because it has detected an unusual temperature difference between the water leaving the boiler and the water returning to it.

Medium Engineer only £120-£250

Parts commonly replaced

  • CH Return Temperature Sensor
  • CH Flow Temperature Sensor
  • Circulating Pump

Related codes

E82

Your boiler has stopped working because the flame kept going out repeatedly in a short space of time.

High Engineer only £150-350

Parts commonly replaced

  • Flame sensor/electrode
  • Gas valve
  • Ignition lead

Related codes

F07

Your boiler has automatically shut down because the exhaust gases getting rid of the smoke and fumes have become dangerously hot.

Emergency Engineer only £150-350

Parts commonly replaced

  • Flue gas sensor
  • NTC thermistor
  • Heat exchanger
  • Main PCB

Related codes

F13

Your boiler has locked itself out because the reset button has been pressed too many times in a short period.

Medium DIY-safe

What to check first

  1. Turn off the boiler at the main power switch or unplug it from the wall.
  2. Wait for approximately 5 to 10 minutes to let the internal system and electronics clear.
  3. Turn the power back on and, if necessary, press the reset button once to see if normal operation resumes.

Related codes

F34

Your boiler has detected that the electrical supply voltage coming from your home's mains is too low to run it safely.

High Engineer only £90-180

Parts commonly replaced

  • Main PCB
  • Internal wiring fuse

Related codes

F37

Your boiler has stopped working because the water pressure inside the system has dropped too low.

High DIY-safe

What to check first

  1. Locate the filling loop valves beneath your boiler.
  2. Open the valves gently to let water in, watching the pressure gauge on the front of the boiler.
  3. Stop filling when the needle reaches between 1.0 and 1.5 bar, then firmly close the valves.

Parts commonly replaced

  • Pressure Relief Valve
  • Pressure Sensor
  • Expansion Vessel

Related codes

Showing 21–28 of 28
F39

Your boiler is having trouble communicating with the optional sensor that measures the temperature outside your home.

Low Engineer only £90-160

Parts commonly replaced

  • Outdoor temperature sensor
  • Wiring connection
F40

Your boiler has temporarily stopped working because the water pressure inside the system has risen higher than it should be.

Medium DIY-safe £90-180

What to check first

  1. Locate the filling loop valves beneath your boiler and ensure they are fully closed.
  2. Bleed one or two of your radiators slightly using a radiator key to release excess water and pressure.
  3. Check the boiler pressure gauge until it drops back down into the normal green zone (usually between 1 and 1.5 bar).

Parts commonly replaced

  • Pressure relief valve
  • Expansion vessel
  • Pressure sensor

Related codes

F47

Your boiler has temporarily stopped working because it cannot accurately read the water pressure inside the system.

High Engineer only £90-180

Parts commonly replaced

  • Water Pressure Sensor
  • Pressure Sensor Wiring Harness

Related codes

F50

Your boiler is having trouble reading the temperature of your hot water cylinder, which means it may not be heating your water properly.

Medium Engineer only £90-180

Parts commonly replaced

  • NTC Sensor
  • Wiring Harness

Related codes

F51

Your boiler has detected an issue with the external temperature sensor used for a solar heating system, meaning it cannot accurately read the solar panel temperature.

Low Engineer only £90-180

Parts commonly replaced

  • PT1000 Solar Sensor
  • Sensor Wiring Harness

Related codes

F52

Your boiler has detected an issue with the sensor that measures the temperature of your hot water, meaning you may currently have no hot water.

High Engineer only £100-£200

Parts commonly replaced

  • DHW Temperature Sensor
  • Wiring Harness

Related codes

F53

Your boiler has temporarily stopped working because it has detected an issue with the sensor that monitors the temperature of the exhaust gases.

High Engineer only £120-250

Parts commonly replaced

  • Flue gas temperature sensor
  • Wiring harness

Related codes

F81

Your boiler has paused because its internal temperature sensors are reading different measurements, which is a safety check to prevent overheating.

Medium Engineer only £100-250

Parts commonly replaced

  • NTC Temperature Sensor
  • Flow and Return Thermistors

Related codes

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