ECA Confeo Premix HM Fault codes & diagnostics

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

Combi Natural Gas 2020-present
GC Numbers 47-814-1547-814-1647-814-1747-814-1847-814-1947-814-20
Download the ECA Confeo Premix HM manual The official installation & service manual (PDF) — the exact document these fault codes were verified against. PDF

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

Severity at a glance

Each cell = one fault code. Hover to identify.
1 Emergency 35 High 2 Medium
Versions & GC numbers

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
47-814-17 Confeo Premix P 24 HM NG ERP YBK UK 2020–present
47-814-18 Confeo Premix P 28 HM NG ERP YBK UK 2020–present
47-814-19 Confeo Premix P 30 HM NG ERP YBK UK 2020–present
47-814-20 Confeo Premix P 35 HM NG ERP YBK UK 2020–present
Just want the most common ECA Confeo Premix HM faults?
The top 6 problems in plain English — with causes, DIY checks and repair costs.
Fault codes

All 38 documented codes

Tap any card for details

E01

Your boiler has failed to light the flame, which means it cannot provide any heating or hot water until the issue is resolved.

High DIY-safe £100-350

What to check first

  1. Check that your gas supply is turned on at the meter
  2. Prepaid meter users: ensure you have credit and the valve hasn't closed
  3. Press and hold the 'R' (Reset) button for 3-5 seconds to see if the boiler restarts
  4. Check if other gas appliances in your home, like a hob, are working correctly

Parts commonly replaced

  • Ignition electrode
  • Gas valve
  • Spark generator
  • PCB

Related codes

Full explanation for E01
E02

Your boiler thinks a flame is present even though no gas should be flowing, which is a safety conflict that has caused the system to lock itself down.

High DIY-safe £120-280

What to check first

  1. Press the Reset button on the control panel once
  2. Ensure there is no moisture around the display or controls
  3. If the fault returns immediately after resetting, turn off the boiler and call a Gas Safe engineer

Parts commonly replaced

  • Ionisation Electrode
  • Gas Valve
  • Printed Circuit Board (PCB)

Related codes

Full explanation for E02
E03

Your boiler has shut down because the water inside it has become too hot and cannot circulate properly.

High DIY-safe £120-300

What to check first

  1. Check that all boiler valves underneath the unit are fully open.
  2. Ensure that at least one radiator (usually the one in the hallway) has its valves turned fully to the open position.
  3. Press the Reset button on the control panel once.
  4. Check that your heating system pressure gauge is between 1 and 1.5 bar.

Parts commonly replaced

  • Circulation Pump
  • Overheat Thermostat
  • NTC Temperature Sensor

Related codes

Full explanation for E03
E15

Your boiler has shut down because its internal sensors are giving conflicting or incorrect temperature readings.

High DIY-safe £90-180

What to check first

  1. Press the Reset button on the control panel to clear the temporary lockout
  2. Monitor the boiler to see if the error code returns immediately
  3. Ensure there is sufficient water pressure in the system (typically between 1 and 1.5 bar)

Parts commonly replaced

  • NTC Temperature Sensor
  • Heat Exchanger Sensor
  • Wiring harness / sensor connections

Related codes

Full explanation for E15
E16

Your boiler has stopped working because it cannot detect how hot the water is going into your radiators.

High DIY-safe £90-160

What to check first

  1. Press the Reset button on the control panel
  2. Check if the boiler fires up and remains operational
  3. If the code returns immediately, do not attempt further repairs and call a professional

Parts commonly replaced

  • Central Heating Flow NTC Sensor
  • Wiring harness / Connector

Related codes

Full explanation for E16
E17

Your boiler has stopped working because it cannot detect the temperature of the water returning to the unit, causing it to shut down for safety.

High Engineer only £90-180

What to check first

  1. Press the Reset button once to see if the error clears
  2. Check that your central heating valves are fully open
  3. Ensure your system pressure is between 1 and 1.5 bar

Parts commonly replaced

  • Return NTC Temperature Sensor
  • Sensor wiring harness
  • Main PCB

Related codes

Full explanation for E17
E18

Your boiler has sensed a sudden, unusual spike in temperature and has shut down as a safety precaution.

High DIY-safe £90-180

What to check first

  1. Press the Reset button on the control panel to clear the lockout.
  2. Check that your radiator valves are open to ensure water can flow through the system.
  3. Ensure your system pressure is topped up to between 1 and 1.5 bar.

Parts commonly replaced

  • Temperature Sensor (NTC Thermistor)
  • Circulation Pump

Related codes

Full explanation for E18
E33

Your boiler has detected a fault with the sensor that monitors water returning to the unit, causing it to shut down for safety.

High Engineer only £90-160

What to check first

  1. Press the Reset button once to see if the error clears
  2. Check that all radiator valves are open to ensure water can flow back to the boiler
  3. If the code returns immediately, do not attempt further repairs and call a Gas Safe engineer

Parts commonly replaced

  • Return water temperature sensor (NTC thermistor)
  • Wiring harness / sensor connections

Related codes

Full explanation for E33
E35

Your boiler has stopped working because the sensor that measures the temperature of the water leaving the unit has failed or has a faulty connection.

High Engineer only £90-160

What to check first

  1. Press the Reset button once to see if the error clears
  2. Ensure all power to the boiler is turned off and back on to cycle the system
  3. Contact a Gas Safe registered engineer if the code reappears immediately

Parts commonly replaced

  • Flow Temperature Sensor (NTC thermistor)
  • Wiring harness / sensor cable

Related codes

Full explanation for E35
E38

Your boiler has detected a sudden drop in water pressure shortly after being refilled, which usually means there is a leak somewhere in your heating system or inside the unit itself.

High DIY-safe £100-350

What to check first

  1. Check your radiators, valves, and visible pipework for any signs of water leaks
  2. Top up the system pressure using the filling loop until the gauge reads between 1.0 and 1.5 bar
  3. Press the Reset button on the control panel
  4. Monitor the pressure gauge closely; if it drops again quickly, turn off the boiler and call a professional

Parts commonly replaced

  • Automatic Air Vent
  • Pressure Relief Valve
  • Expansion Vessel
  • Radiator Valve Seals

Related codes

Full explanation for E38
Showing 11–20 of 38
E44

Your boiler has stopped working because the gas valve is not communicating correctly with the main control board.

High Engineer only £180-£350

What to check first

  1. Locate the reset button on the control panel
  2. Press and hold the reset button for 3 seconds
  3. Monitor the boiler to see if it fires up normally or if the code returns

Parts commonly replaced

  • Gas Valve
  • Main PCB (Control Board)
  • Wiring Loom

Related codes

Full explanation for E44
E64

Your boiler has encountered a computer or electronic hardware error that has caused it to stop working for safety reasons.

High DIY-safe £180-350

What to check first

  1. Locate the main power switch or boiler dial
  2. Turn the boiler off for at least 30 seconds
  3. Turn the boiler back on and wait to see if the code clears

Parts commonly replaced

  • Main Printed Circuit Board (PCB)
  • Wiring Harness

Related codes

Full explanation for E64
E65

Your boiler has encountered a computer-related error that is preventing it from running safely.

High DIY-safe £180-£350

What to check first

  1. Switch the boiler off at the main electrical fused spur switch.
  2. Wait for 60 seconds.
  3. Switch the power back on and see if the error clears.

Parts commonly replaced

  • Main Printed Circuit Board (PCB)
  • Electronic Control Module

Related codes

Full explanation for E65
E80

Your boiler has shut down because it thinks the water returning from your radiators is hotter than the water leaving the boiler, which usually indicates a sensor error or a circulation problem.

High DIY-safe £120-250

What to check first

  1. Press the Reset button on the control panel to clear the temporary lockout.
  2. Check that all radiator valves are fully open and your home's thermostat is calling for heat.
  3. Ensure the boiler pressure is between 1.0 and 1.5 bar on the pressure gauge.

Parts commonly replaced

  • Return temperature sensor (NTC)
  • Flow temperature sensor (NTC)
  • Circulation pump

Related codes

Full explanation for E80
E82

Your boiler is failing to keep a steady flame alight and has locked itself out for safety after multiple failed attempts.

High DIY-safe £100-280

What to check first

  1. Press the Reset button once to see if the fault was temporary
  2. Check that your gas pre-payment meter (if applicable) has credit
  3. Ensure that other gas appliances in your home, such as a hob, are working correctly

Parts commonly replaced

  • Flame sensing electrode (Ionisation probe)
  • Ignition lead
  • Gas valve
  • Printed Circuit Board (PCB)

Related codes

Full explanation for E82
E83

Your boiler has shut down because the exhaust fumes have become too hot, which suggests a blockage or a build-up of debris inside the main heat exchanger.

High Engineer only £180-600

Parts commonly replaced

  • Main Heat Exchanger
  • Flue Gas Sensor
  • Burner Gaskets

Related codes

Full explanation for E83
E98

Your boiler's internal computer has encountered a critical electronic failure that it cannot automatically recover from.

High Engineer only £250-450

What to check first

  1. Locate the main power switch for the boiler
  2. Switch it off and wait for 30 seconds
  3. Switch it back on and check if the error clears

Parts commonly replaced

  • Main Printed Circuit Board (PCB)
  • Control Panel Assembly

Related codes

Full explanation for E98
E99

Your boiler has encountered a deep-seated electronic internal error that has caused it to shut down for safety.

High DIY-safe £280-450

What to check first

  1. Locate the power switch or fused spur for the boiler
  2. Turn the power off and wait for 30 seconds
  3. Turn the power back on and see if the error clears

Parts commonly replaced

  • Main Printed Circuit Board (PCB)
  • Electronic Control Unit

Related codes

Full explanation for E99
F05

Your boiler has stopped working because the internal fan, which safely pushes exhaust gases out of the flue, is not spinning correctly.

High Engineer only £220-450

What to check first

  1. Locate the reset button on the boiler control panel
  2. Press and hold the reset button for 3 to 5 seconds
  3. If the code returns immediately, do not attempt to open the boiler casing; contact a Gas Safe engineer

Parts commonly replaced

  • Fan assembly
  • Fan wiring harness
  • Main PCB (Printed Circuit Board)

Related codes

Full explanation for F05
F07

Your boiler has sensed that the exhaust gases are getting too hot and has shut down to prevent damage to the internal components.

High Engineer only £120-£350

Parts commonly replaced

  • Heat exchanger
  • Flue gas NTC sensor
  • Main PCB

Related codes

Full explanation for F07
Showing 21–30 of 38
F10

Your boiler has stopped working because water is not flowing through the system properly, often due to a blockage or a build-up of debris.

High DIY-safe £100-£450

What to check first

  1. Check that your boiler pressure is between 1.0 and 1.5 bar on the gauge.
  2. Ensure all radiator valves and internal isolation valves are fully open.
  3. Gently bleed your radiators to remove any trapped air pockets.
  4. Restart the boiler to see if the error clears.

Parts commonly replaced

  • Circulation pump
  • Main heat exchanger (de-scaling)
  • Central heating filter
  • Flow temperature sensor

Related codes

Full explanation for F10
F13

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

High Engineer only £80-250

Parts commonly replaced

  • Main PCB
  • Ignition Electrode
  • Gas Valve

Related codes

Full explanation for F13
F34

Your boiler has stopped working because the electrical power coming from your mains supply is too low for it to run safely.

High Engineer only £100-350

Parts commonly replaced

  • Printed Circuit Board (PCB)
  • Voltage Regulator/Protector

Related codes

Full explanation for F34
F36

Your boiler has detected an issue with the stability or frequency of your home's electrical supply, causing it to shut down for safety.

High Engineer only £100-£350

Parts commonly replaced

  • Printed Circuit Board (PCB)
  • Surge Protector

Related codes

Full explanation for F36
F37

Your boiler has stopped working because the water pressure is too low for the system to run safely.

High DIY-safe £0-120

What to check first

  1. Locate the filling loop (usually a silver flexible hose) underneath or near the boiler.
  2. Slowly open the one or two taps/levers on the filling loop until you hear water rushing.
  3. Watch the pressure gauge and close the taps once the needle reaches 1.5 bar.
  4. Ensure the taps are fully closed and the error code should clear automatically.

Parts commonly replaced

  • Water pressure sensor
  • Filling loop valve
  • Expansion vessel

Related codes

Full explanation for F37
F39

Your boiler is having trouble reading the temperature outside, which is preventing it from working correctly.

High DIY-safe £90-160

What to check first

  1. Press the Reset button on the boiler control panel
  2. Check if any external wires leading to a sensor on an outside wall are visibly damaged
  3. If the fault persists after resetting, you will need a professional to test the sensor

Parts commonly replaced

  • Outdoor temperature sensor (weather compensator)
  • External sensor wiring
  • Main PCB

Related codes

Full explanation for F39
F40

Your boiler has shut down because there is too much water in the system, causing the pressure to rise above a safe limit.

Emergency DIY-safe £80-180

What to check first

  1. Check that the filling loop valves (under the boiler) are tightly closed.
  2. Locate a radiator and use a bleed key to release water into a container until the pressure gauge on the boiler drops to between 1.0 and 1.5 bar.
  3. Turn the boiler off and back on again to reset the fault.

Parts commonly replaced

  • Filling loop valve
  • Expansion vessel
  • Water pressure sensor

Related codes

Full explanation for F40
F41

Your boiler is automatically trying to refill but has been running for too long, suggesting an internal leak or a filling valve error.

High Engineer only £120-250

Parts commonly replaced

  • Automatic filling valve
  • Main PCB
  • Pressure sensor

Related codes

Full explanation for F41
F42

Your boiler is struggling to automatically fill itself with water to the required pressure level.

High DIY-safe £120-250

What to check first

  1. Check that your main water stop tap is fully open
  2. Ensure there are no active water leaks in your home
  3. Try resetting the boiler to see if the auto-fill sequence restarts

Parts commonly replaced

  • Automatic filling valve
  • Water pressure sensor
  • Flow meter

Related codes

Full explanation for F42
F43

Your boiler has tried to top up its internal water pressure automatically but failed, meaning there is not enough water in the system to operate safely.

High DIY-safe £90-220

What to check first

  1. Check that your main water supply stopcock is fully open
  2. Ensure there are no visible leaks from radiators or pipework
  3. Try to manually increase the system pressure to 1.5 bar using the filling loop if accessible
  4. Reset the boiler once the pressure is restored

Parts commonly replaced

  • Automatic filling valve
  • Water pressure sensor
  • External filling loop

Related codes

Full explanation for F43
Showing 31–38 of 38
F47

Your boiler has stopped working because it cannot detect the water pressure, likely due to a loose connection or a faulty internal sensor.

High DIY-safe £100-190

What to check first

  1. Press the 'Reset' button on the boiler control panel once
  2. Check if the boiler pressure gauge is between 1 and 1.5 bar
  3. If the code returns immediately, do not attempt further repairs and contact a professional

Parts commonly replaced

  • Water pressure sensor
  • Wiring harness / connector

Related codes

Full explanation for F47
F49

Your boiler is having trouble communicating with your room thermostat, which means it isn't receiving instructions on when to turn the heating on or off.

High DIY-safe £90-250

What to check first

  1. Locate the main power switch for your boiler and turn it off for 30 seconds, then turn it back on.
  2. Press the 'Reset' button on the boiler control panel.
  3. If you have a wireless thermostat, check and replace the batteries to ensure it has enough power to send a signal.

Parts commonly replaced

  • Room Thermostat
  • Receiver Unit
  • Main Control Board (PCB)

Related codes

Full explanation for F49
F50

Your boiler has lost communication with the temperature sensor in your hot water storage tank, meaning it cannot safely heat your water.

High Engineer only £90-160

Parts commonly replaced

  • NTC Storage Tank Sensor
  • Wiring harness
  • Main PCB

Related codes

Full explanation for F50
F51

Your boiler has detected a problem with the temperature sensor for your solar heating system, which is causing the unit to stop operating as a precaution.

Medium DIY-safe £90-160

What to check first

  1. Locate the 'Reset' button on the boiler control panel.
  2. Press and hold the button for 3 seconds to clear the fault.
  3. If the error returns immediately or frequently, contact a qualified technician to check the sensor wiring.

Parts commonly replaced

  • PT1000 Solar Temperature Sensor
  • Sensor wiring harness

Related codes

Full explanation for F51
F52

Your boiler has detected a problem with the sensor that monitors your hot water temperature, which means you likely have no hot water or the temperature is inconsistent.

Medium Engineer only £90-160

Parts commonly replaced

  • DHW Temperature Sensor (NTC Thermistor)
  • Wiring harness/connector

Related codes

Full explanation for F52
F53

Your boiler has detected a problem with the sensor that monitors the temperature of the exhaust fumes and has stopped running for safety.

High Engineer only £90-180

Parts commonly replaced

  • Flue gas temperature sensor (NTC)
  • Wiring harness connector

Related codes

Full explanation for F53
F81

Your boiler has detected that its temperature sensors are giving conflicting readings and has shut down to prevent overheating.

High Engineer only £90-180

Parts commonly replaced

  • NTC Temperature Sensor
  • Wiring Harness
  • Main PCB

Related codes

Full explanation for F81
F201

Your boiler’s internal control panels aren't talking to each other correctly, meaning the boiler has temporarily shut down to prevent further issues.

High Engineer only £180-450

Parts commonly replaced

  • Main Printed Circuit Board (PCB)
  • MMI Control Display Board
  • Communication Cable Loom

Related codes

Full explanation for F201
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