Alpha Eco 11 13 Fault codes & diagnostics

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

Combi Natural Gas 11-13 kW 2013-2019 Discontinued
GC Number 47-532-59

Replaced by: E-Tec Regular

Download the Alpha Eco 11 13 manual The official installation & service manual (PDF) — the exact document these fault codes were verified against. PDF

The fault code is already on your display

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 19 High 3 Medium 1 Low
Just want the most common Alpha Eco 11 13 faults?
The top 6 problems in plain English — with causes, DIY checks and repair costs.
Fault codes

All 24 documented codes

Tap any card for details

01

Your boiler has tried to light several times but cannot establish a flame, meaning your heating and hot water will not work.

High DIY-safe £120-350

What to check first

  1. Check if other gas appliances, like a hob, are working to ensure gas is reaching the property.
  2. Verify that your gas meter has credit if you have a pre-payment meter.
  3. Press and hold the 'R' or reset button for a few seconds to see if the boiler restarts.
  4. During freezing weather, check if the white plastic condensate pipe leading outside is frozen and thaw it with warm water.

Parts commonly replaced

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

Related codes

Full explanation for 01
02

Your boiler has become too hot and has shut down as a safety precaution to prevent damage.

High DIY-safe £100-£350

What to check first

  1. Wait 30 minutes for the boiler to cool down naturally.
  2. Ensure all radiator valves are fully open and there are no blockages.
  3. Press and hold the reset button for a few seconds to restart the system.

Parts commonly replaced

  • Overheat Thermostat
  • Circulation Pump
  • Primary Heat Exchanger

Related codes

Full explanation for 02
03

Your boiler has detected that the exhaust gases leaving the unit are getting dangerously hot, so it has automatically shut down to prevent damage.

High Engineer only £150-300

Parts commonly replaced

  • Flue thermostat
  • Primary heat exchanger
  • System pump

Related codes

Full explanation for 03
04

Your boiler has detected an electrical connection problem between the main control board and the gas valve, meaning it cannot safely ignite to provide heat or hot water.

High Engineer only £120-£350

Parts commonly replaced

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

Related codes

Full explanation for 04
05

Your boiler has detected a problem with the internal sensor that monitors the temperature of the water heading to your radiators, causing the system to stop working for safety.

High Engineer only £90-160

Parts commonly replaced

  • Central heating flow NTC sensor
  • Wiring harness connector

Related codes

Full explanation for 05
06

Your boiler is having trouble detecting the temperature of your hot water, which usually means it cannot heat water for your taps.

Medium Engineer only £90-160

Parts commonly replaced

  • DHW NTC Temperature Sensor
  • Wiring harness connection

Related codes

Full explanation for 06
08

Your boiler has been manually reset too many times in a short period and has now locked itself to prevent potential damage from recurring underlying faults.

High Engineer only £120-250

Parts commonly replaced

  • Main PCB
  • Ignition Transformer
  • Flame Sensor

Related codes

Full explanation for 08
10

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

High DIY-safe £0-120

What to check first

  1. Check the pressure gauge on the front of the boiler; it should ideally be between 1 and 1.5 bar.
  2. Locate the filling loop (usually a silver braided hose with one or two small taps underneath the boiler).
  3. Slowly open the tap(s) until you hear water entering and see the pressure gauge rise to 1.2 bar, then close them tightly.

Parts commonly replaced

  • Filling loop
  • Pressure switch
  • Expansion vessel recharge

Related codes

Full explanation for 10
12

Your boiler is struggling to read the temperature of your hot water cylinder, which is likely preventing your hot water from heating up correctly.

High Engineer only £90-180

Parts commonly replaced

  • NTC Indirect Cylinder Sensor
  • Wiring harness

Related codes

Full explanation for 12
15

Your boiler has detected a problem with its internal electrical connections, meaning it cannot communicate properly with its own parts.

High Engineer only £120-250

Parts commonly replaced

  • Wiring harness
  • PCB (Printed Circuit Board)

Related codes

Full explanation for 15
Showing 11–20 of 24
16

Your boiler has stopped working because the fan that helps remove waste gases is not spinning at the correct speed.

High Engineer only £180-£350

Parts commonly replaced

  • Extractor Fan
  • PCB (Printed Circuit Board)
  • Wiring harness

Related codes

Full explanation for 16
20

Your boiler thinks a flame is still burning even though it has been told to turn off, causing the system to shut down for safety.

High Engineer only £120-£350

Parts commonly replaced

  • Ionisation probe
  • Gas valve
  • Main PCB

Related codes

Full explanation for 20
24

Your boiler has detected that one of the control buttons is stuck or is being pressed for too long, preventing you from changing settings.

Medium DIY-safe £100-250

What to check first

  1. Gently press and release each button on the control panel to see if any feel stuck or 'mushy'.
  2. Wipe the control panel with a dry, lint-free cloth to ensure there is no debris or sticky residue trapping a button.
  3. Perform a power reset by turning the boiler off at the fused spur switch for 30 seconds, then turning it back on.

Parts commonly replaced

  • User Interface (PCB)
  • Control Panel Housing

Related codes

Full explanation for 24
25

Your boiler has detected that it is getting too hot and has automatically shut itself down to prevent damage.

High Engineer only £120-250

Parts commonly replaced

  • Pump
  • Diverter valve
  • Heat exchanger
  • NTC thermistor

Related codes

Full explanation for 25
27

Your boiler is struggling to move water through the system, which is causing it to overheat and shut down for safety.

High DIY-safe £120-£350

What to check first

  1. Check that all your radiator valves (TRVs) are turned to the highest setting
  2. Ensure your boiler pressure is between 1.0 and 1.5 bar
  3. Bleed your radiators to remove any trapped air

Parts commonly replaced

  • Circulation pump
  • Main heat exchanger
  • Flow/Return thermistors

Related codes

Full explanation for 27
29

Your boiler has stopped working because it cannot correctly measure the temperature of the exhaust gases leaving the system.

High Engineer only £120-220

Parts commonly replaced

  • Flue Thermistor / NTC Sensor
  • Wiring Harness
  • Main PCB

Related codes

Full explanation for 29
31

Your boiler has lost its connection with the external thermostat or control panel, meaning it cannot receive instructions to turn the heating on.

High DIY-safe £0-180

What to check first

  1. Check if your wireless thermostat has run out of batteries and replace them if necessary
  2. Ensure the thermostat is within range of the boiler and hasn't been moved too far away
  3. Turn the electrical power to the boiler off and back on again after 30 seconds to restart the connection

Parts commonly replaced

  • Thermostat batteries
  • RF Receiver
  • Room thermostat unit
Full explanation for 31
37

Your boiler is not receiving enough electrical power from the mains supply to operate safely and has shut down as a result.

High Engineer only £100-280

Parts commonly replaced

  • Printed Circuit Board (PCB)
  • External Power Supply Components

Related codes

Full explanation for 37
38

Your boiler started to heat up but the flame went out unexpectedly, causing the system to stop working for safety.

High DIY-safe £120-280

What to check first

  1. Check if other gas appliances, like a hob, are working to ensure gas is reaching the property
  2. Check that your gas meter has credit if you use a pre-payment meter
  3. Try resetting the boiler by turning the selector switch to the 'R' position for 5 seconds

Parts commonly replaced

  • Ignition electrode
  • Flame sensing probe
  • Gas valve

Related codes

Full explanation for 38
43

Your boiler is starting up but struggling to keep the flame alight, causing it to shut down for safety.

High Engineer only £120-280

Parts commonly replaced

  • Flame sensing electrode
  • Ignition lead
  • Gas valve
  • PCB
Full explanation for 43
Showing 21–24 of 24
44

Your boiler has detected a potential safety issue and has shut itself down to prevent any harm.

Emergency Engineer only £150-300

Parts commonly replaced

  • Gas valve
  • Ignition electrode
  • Printed Circuit Board (PCB)

Related codes

Full explanation for 44
46

Your boiler has lost its connection to the outside temperature sensor, meaning the system doesn't know how hard it needs to work to heat your home.

Low Engineer only £90-180

Parts commonly replaced

  • External temperature sensor
  • Wiring harness

Related codes

Full explanation for 46
47

Your boiler is working at a lower power than usual because it has detected that the exhaust gases are getting too hot.

Medium Engineer only £120-280

Parts commonly replaced

  • Heat Exchanger (Cleaning/Descaling)
  • Flue Thermostat
  • Main Heat Exchanger

Related codes

Full explanation for 47
51

Your boiler has lost its wireless connection with your thermostat or remote control, meaning they can no longer talk to each other to manage your heating.

High DIY-safe £0-180

What to check first

  1. Check and replace the batteries in your wall-mounted thermostat or remote transmitter
  2. Ensure the thermostat is within range of the boiler and not blocked by large metal objects
  3. Try to re-pair the device to the boiler receiver following the instructions in your user manual

Parts commonly replaced

  • Thermostat batteries
  • Wireless RF transmitter
  • Boiler receiver PCB
Full explanation for 51
Status & diagnostic codes

10 operating states & engineer diagnostics

Not faults — these are normal operating states. Tap to expand.

d0 Diagnostic Your boiler is displaying a code that is not actually used by the manufacturer, suggesting an internal software glitch or a communication error between its components. d1 Diagnostic Your boiler is displaying a real-time measurement of the flame signal, which is a status indication rather than a fault, meaning the system is currently monitoring its burner performance. d2 Diagnostic The display is simply showing you the current temperature of the hot water being sent to your radiators, rather than indicating a fault. d3 Diagnostic Your boiler is simply displaying the current temperature of the hot water as it leaves the unit, rather than an error message indicating a breakdown. d4 Diagnostic Your boiler is simply displaying the current target temperature setting for your radiators, and there is no actual fault with the appliance. d5 Diagnostic Your boiler is simply displaying the temperature setting you have chosen for your hot water, rather than indicating a technical fault. d6 Diagnostic Your boiler is struggling to read the temperature from the sensor located outside your home, which helps it adjust its heat output based on the weather. d7 Diagnostic Your boiler is struggling to read the temperature of the incoming water or the water stored in your hot water cylinder, which may result in inconsistent heating or hot water performance. d8 Diagnostic Your boiler has encountered an undefined internal software error that requires a professional to investigate and reset the system. d9 Diagnostic Your boiler is simply displaying a list of its past recorded issues, rather than indicating a current problem.