Ideal Mini C32 Fault codes & diagnostics

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

Combi Natural Gas 32 kW 2006-2010 Discontinued

Replaced by: Logic Combi

This boiler uses LED flash patterns

Count the flashes in one repeating group before the pause. That number is your fault code. Do not reset until you have noted it. How to read fault codes →

Severity at a glance

Each cell = one fault code. Hover to identify.
4 Emergency 35 High 7 Medium 1 Low

All 47 documented codes

Tap any card for details

LED 1 fast pulse

Your boiler has detected a minor electronic sensor issue and is running at a lower power level to keep your home warm until it can be serviced.

Low Engineer only £90-180

Parts commonly replaced

  • NTC Temperature Sensor
  • PCB Connection
LED1 flashing, LED2 on

Your boiler has detected a problem with the sensor that monitors the temperature of your central heating water, meaning it can't heat your radiators safely.

High Engineer only £90-160

Parts commonly replaced

  • Central Heating NTC Thermistor
  • Thermistor Wiring Harness

Related codes

LED1 on, LED2 flashing

Your boiler has detected a problem with how it moves air and exhaust gases through the system, preventing it from firing up safely.

High Engineer only £120-280

Parts commonly replaced

  • Air Pressure Switch
  • Fan Assembly
  • Venturi Tube
LED2 flashing, LED3 on

Your boiler has detected a sensor problem that is preventing it from providing hot water correctly.

Medium Engineer only £90-160

Parts commonly replaced

  • DHW Thermistor (NTC Sensor)
  • Wiring Harness
Lock-out signal lamp E blinks

Your boiler has tried to start up but failed to ignite the gas flame, causing the system to shut down for safety.

High DIY-safe £120-350

What to check first

  1. Check that your gas prepay meter has credit
  2. Ensure other gas appliances in your home (like a hob) are working
  3. Press the reset button once to see if the boiler restarts

Parts commonly replaced

  • Ignition Electrode
  • Gas Valve
  • Flame Sensing Probe
  • PCB
164-026

Your boiler has stopped working because a sensor that measures water temperature is providing an incorrect reading or has become disconnected.

High Engineer only £120-220

Parts commonly replaced

  • NTC Temperature Sensor
  • Wiring harness
169-033

There is a minor leak from a seal within the boiler's internal plumbing which needs to be tightened or replaced to stop water dripping inside the unit.

Medium Engineer only £100-180

Parts commonly replaced

  • 3/4 inch fibre washer
  • Rubber O-ring seal
169-083

Your boiler has stopped working because an internal electrical safety fuse has blown, cutting off power to the system's control board.

High Engineer only £120-220

Parts commonly replaced

  • 1.6A T fuse
  • Printed Circuit Board (PCB)
169-127

Your boiler is failing to detect the correct airflow needed to operate safely, which is preventing it from firing up.

High Engineer only £150-250

Parts commonly replaced

  • Air pressure switch
  • Venturi
  • Flue fan
169-141

There is a small physical seal inside your boiler that has likely failed, causing a internal water drip.

Medium Engineer only £120-200

Parts commonly replaced

  • 1/2 inch fiber washer
  • Internal water seals
Showing 11–20 of 47
E00-684

Your boiler is struggling to detect the movement of water inside the system, which is preventing it from safely starting up to provide heat or hot water.

High Engineer only £150-250

Parts commonly replaced

  • Flow switch
  • Diverter valve diaphragm
  • Wiring harness

Related codes

E00-688

Your boiler is failing to detect that water is moving through the system, which means it cannot safely turn on your heating or hot water.

High Engineer only £150-250

Parts commonly replaced

  • Flow switch diaphragm
  • Flow switch microswitch

Related codes

E01

Your boiler has tried to start up but cannot light the gas flame, which means your heating and hot water will not work.

High DIY-safe £90-280

What to check first

  1. Check that your gas pre-payment meter has credit
  2. Ensure the gas stopcock is fully open and other gas appliances like the hob are working
  3. Press and hold the reset button for five seconds

Parts commonly replaced

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

Related codes

E01-156

Your boiler has detected an issue with the fuel supply components specific to LPG operation, meaning it cannot safely ignite.

Emergency Engineer only £150-300

Parts commonly replaced

  • Gas valve
  • Burner injectors
  • Ignition lead
E02

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

High DIY-safe £120-250

What to check first

  1. Check that your radiator valves are open and not turned to off
  2. Ensure there is enough water pressure in the system (check the gauge reads between 1 and 1.5 bar)
  3. Press and hold the reset button for a few seconds to see if the boiler restarts

Parts commonly replaced

  • Overheat Thermostat
  • Pump
  • Thermistor

Related codes

E03

Your boiler has stopped working because it cannot safely clear waste gases through the ventilation pipe.

High Engineer only £120-£280

Parts commonly replaced

  • Fan unit
  • Air pressure switch
  • Flue venturi

Related codes

E05

Your boiler has detected a fault with the sensor that monitors the temperature of the water leaving the unit to heat your radiators.

High Engineer only £90-160

Parts commonly replaced

  • Central Heating Flow NTC Thermistor
  • Wiring harness connector

Related codes

E06

Your boiler is having trouble measuring the temperature of your hot water, which usually means it cannot provide consistent heat to your taps.

Medium Engineer only £90-160

Parts commonly replaced

  • Domestic Hot Water (DHW) thermistor
  • NTC sensor
  • Wiring harness

Related codes

E15

Your boiler has detected a problem with the sensor that monitors the temperature of the water coming back into the unit, preventing it from heating correctly.

High Engineer only £90-160

Parts commonly replaced

  • Return thermistor (NTC sensor)
  • Wiring harness / connector

Related codes

E16

Your boiler has detected that there is not enough water in the system to operate safely, causing it to shut down temporarily.

High DIY-safe £60-140

What to check first

  1. Locate the filling loop (the flexible silver hose) underneath your boiler.
  2. Slowly open the valve(s) to allow water into the system while watching the pressure gauge.
  3. Close the valves tightly once the gauge reaches between 1.0 and 1.5 bar.
  4. Press the reset button on the boiler control panel.

Parts commonly replaced

  • Water pressure switch
  • Filling loop valve

Related codes

Showing 21–30 of 47
E22

Your boiler's internal computer brain has lost its configuration settings and needs a professional to reset or replace it.

High Engineer only £250-450

Parts commonly replaced

  • Main Printed Circuit Board (PCB)
  • Internal Wire Harness

Related codes

E35

Your boiler has sensed a flame after it should have gone out, or before it has even started, causing it to shut down for safety.

High Engineer only £120-£350

Parts commonly replaced

  • Ionisation probe
  • Gas valve
  • Main PCB
E57-048

Your boiler is struggling to heat your tap water because an internal seal or flow component is faulty, causing the system to stop working properly.

High Engineer only £180-300

Parts commonly replaced

  • Plate heat exchanger
  • Heat exchanger O-rings

Related codes

E57-049

Your boiler is having difficulty transferring heat to your hot water supply, likely due to a blockage or a leak within the internal heat exchanger component.

High Engineer only £250-400

Parts commonly replaced

  • Plate heat exchanger
  • O-ring set
E69-243

Your boiler has detected an issue with the seal around the observation window, which could lead to unsafe gases escaping into your home.

Emergency Engineer only £120-200

Parts commonly replaced

  • Combustion chamber sight glass
  • Gasket seal
E83-013

Your boiler has detected an issue with the pressure relief mechanism, which is designed to prevent dangerous pressure build-up inside the unit.

Emergency Engineer only £150-250

Parts commonly replaced

  • Pressure relief valve
  • Expansion vessel
E83-081

Your boiler is struggling to detect the flow of water because the internal sensor or its protective filter is likely clogged or faulty.

High Engineer only £150-250

Parts commonly replaced

  • Magnetic flow switch
  • System filter
E83-082

Your boiler is failing to detect that you have turned on a hot water tap, so it is not igniting to heat the water.

Medium Engineer only £120-220

Parts commonly replaced

  • DHW flow switch
  • Flow turbine

Related codes

E83-086

Your boiler is struggling to switch between heating your radiators and heating your hot water taps, which may cause one or both to stop working correctly.

High Engineer only £180-350

Parts commonly replaced

  • Diverter valve actuator
  • Diverter valve cartridge

Related codes

E83-101

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

  • High limit thermostat
  • Pump
  • Diverter valve
  • Heat exchanger
Showing 31–40 of 47
E83-122

Your boiler is struggling to detect the flame needed to heat your water, so it has safely shut itself down to prevent any issues.

High Engineer only £120-200

Parts commonly replaced

  • Ignition/detection electrode
  • Ignition lead
  • PCB
E83-126

Your boiler is failing to light the flame properly because it cannot accurately detect or send the spark needed to start the fire.

High Engineer only £120-220

Parts commonly replaced

  • Ignition lead
  • Ignition electrode
  • Printed Circuit Board (PCB)

Related codes

E83-127

Your boiler is failing to detect a flame when it tries to light, so it has safely shut down to prevent gas buildup.

High Engineer only £120-250

Parts commonly replaced

  • Ignition electrode
  • Ignition lead
  • Ignition transformer
  • PCB
E83-142

Your boiler is failing to light the flame properly, which means it has stopped producing heat and hot water as a precaution.

High Engineer only £150-300

Parts commonly replaced

  • Ignition electrode
  • Ignition lead
  • Printed Circuit Board (PCB)
E83-145

Your boiler is struggling to accurately read or maintain the correct pressure and water temperature, often due to a faulty or blocked sensor connection.

Medium Engineer only £150-250

Parts commonly replaced

  • Pressure sensor
  • Temperature sensor
  • Wiring loom
E90-627

Your boiler is failing to light because it cannot properly control the fuel supply, meaning you currently have no heating or hot water.

High Engineer only £250-400

Parts commonly replaced

  • Gas valve
  • Gas valve gasket
Faulty air pressure switch

Your boiler is struggling to confirm it is venting exhaust gases safely, so it has stopped working to prevent any risk.

High Engineer only £150-250

Parts commonly replaced

  • Air pressure switch
  • Venturi nozzle
  • Flue fan
Faulty primary circuit

Your boiler has detected that water is not circulating properly through your heating system, so it has safely shut down to prevent damage.

High DIY-safe £120-250

What to check first

  1. Check your boiler display for the water pressure gauge reading; it should be between 1.0 and 1.5 bar
  2. If the pressure is below 1 bar, use the filling loop underneath the boiler to add water until it reaches 1.5 bar
  3. Turn off the boiler at the wall, wait 30 seconds, and turn it back on to reset the system

Parts commonly replaced

  • Circulation pump
  • Diverter valve
  • Flow switch
H20-986

Your boiler has detected trapped air inside the system, which is preventing water from circulating correctly to provide you with heating and hot water.

Medium Engineer only £120-200

Parts commonly replaced

  • Automatic air vent
  • System pressure sensor
H21-048

Your boiler's fan unit is failing to spin or communicate correctly, which forces the boiler to shut down to prevent unsafe combustion.

High Engineer only £180-350

Parts commonly replaced

  • Fan assembly
  • Wiring harness
  • PCB
Showing 41–47 of 47
H21-049

Your boiler's fan is failing to start or maintain the correct speed, which prevents the unit from safely venting exhaust gases and heating your home.

High Engineer only £180-300

Parts commonly replaced

  • Fan assembly
  • Wiring harness
  • PCB
H21-052

Your boiler has detected that one of its outer side casing panels is not fitted correctly or is loose, which prevents the boiler from operating safely.

High DIY-safe £80-120

What to check first

  1. Switch off the boiler and allow it to cool.
  2. Remove the front cover if necessary to access the side panels.
  3. Check that the side panels are securely clipped into place and the seals are intact.
  4. Ensure all fixing screws are tightened, then restart the boiler.

Parts commonly replaced

  • Side panel clips
  • Outer casing seal
H21-060

Your boiler has detected that the seals around the combustion area are not airtight, which prevents the unit from operating safely.

Emergency Engineer only £150-250

Parts commonly replaced

  • Sealed chamber gasket kit
  • Burner door seal
H21-064

Your boiler has detected that the exhaust gases are getting too hot, so it has turned itself off to prevent overheating.

High Engineer only £150-250

Parts commonly replaced

  • Flue thermostat
  • Heat exchanger
  • PCB
H27-582

Your boiler is failing to detect the airflow needed for safe operation, so it has shut down to prevent any unsafe combustion.

High Engineer only £150-250

Parts commonly replaced

  • Air Pressure Switch
  • Venturi
  • Flue tubes
Lack of burner ignition

Your boiler is trying to start up but cannot light the gas to create a flame, meaning you will have no heating or hot water.

High DIY-safe £120-350

What to check first

  1. Check if other gas appliances, like a hob, are working to confirm gas supply
  2. Verify that your prepaid gas meter (if applicable) has credit
  3. Press the reset button or turn the control knob to 'Reset' for 2 seconds

Parts commonly replaced

  • Ignition electrodes
  • Gas valve
  • Printed Circuit Board (PCB)
  • Ignition lead
Overheat thermostat lockout

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

High Engineer only £120-250

Parts commonly replaced

  • Overheat thermostat
  • Central heating pump
  • Diverter valve
  • PCB