Today, most modern Gas Boilers are equipped to tell you they are experiencing a problem. They do so by flashing fault codes or error codes, and you can see these codes on Boiler's display. If you want to know why your Boiler is not working, the first step is to check if any fault code or error code is displayed. Your entire heating system works in synergy for your house to stay warm. The Fault codes can instruct you where the fault in your heating system lies; that is, the problem could be with water pressure, the pump, power going to the Boiler, and so on. If it is pressure issues, which is the most common, you can top up pressure yourself, but if the problem is technical, you may need to call an expert plumber in Dublin for a diagnosis. That's where Stillorgan Gas, Plumbing, and Electrical can help you with your Gas Boiler Breakdowns and repairs. 

If your Boiler is showing a fault code, here is a quick guide that will help you understand what's wrong with your Boiler and if you need to call a plumber or a heating engineer. 

1.       Ideal Boiler Fault Codes

Did you know: Stillorgan Gas, Plumbing and Electrical are the biggest Ideal Boiler Installer and Repair Company in Dublin.
If your Ideal Boiler is not working, simply Call us

Ideal Boiler F Fault codes

FD – No Water Flow

This is a problem with your boiler's installation. You could try repressurising your boiler to resolve this issue, but if it doesn't work, we recommend contacting your installer to assess and repair your heating system.

F1 – Low Water Pressure

 The Ideal boiler F1 problem is usually self-solvable by increasing your boiler's water pressure to 1.5 using the built-in filling loop. If you continue to have problems, you should call a Gas Safe registered engineer.

F2 – Flame Loss

 Ideal boiler flame loss can be corrected by first checking your other gas appliances and then attempting to reset your boiler. This type of defect is more common in extremely old boilers that are operating at low efficiency, thus it may be more cost-effective to simply purchase a new boiler.

F3 – Fan Fault

This error will require the assistance of a certified engineer.

F4 – Thermistor Fault

It is best to call a Gas Safe registered engineer to fix this problem.

F5 – Return Thermistor Fault

 It is best to call a Gas Safe registered engineer to fix this problem.

F6 – Outside Sensor Fault

The fault may be due to the installation of the weather compensator. If this is not the case, you should contact a qualified engineer to fix it.

F7 – Low Mains Voltage

If your voltage falls below 190 vacs, you may need to contact your installer, but since an electrician might be needed to fix this electrical problem.

F9 – Printed Circuit Board (PCB) Fault

 Investing in a new boiler will be recommended as the cost of repairing these could be very high

Ideal Boiler L Fault Codes

L1 – Lack of Water Flow

 To fix this issue, you should reset your boiler. If these steps do not work, then you should contact a qualified engineer. Overheating is usually a problem with older and less efficient boilers, so investing in a new heating system might be a good idea.

L2 – Ignition Lockout

You may need to reset your Ideal boiler. If there is a rumble from the system, your condensate pipe might be blocked or your flue might be blocked. This type of fault requires the services of an engineer.

L3 – No flow thermistor fault

 This is a complicated fault that requires a call out from a qualified engineer.

L9/H9/HA/LA – Overheating

Please check your system's pressure level, and bleed your radiators to see if this helps. If it does not, contact a Gas Safe registered engineer. The overheating could be caused by a problem with the boiler's pump or dry fire stat.

LF – Boiler fails to ignite

Make sure all other gas appliances in your house are working. If they are, then you can reset your boiler. If your boiler is making an unusual rumbling sound, it could be caused by a blockage in the condensate pipe. A qualified engineer can help you resolve this problem.

L5 – Boiler Return Pipe Problem

This can be resolved by turning off the boiler's power and turning it back on again. If the problem persists, seek the assistance of a qualified engineer.

L6 – Flame Detection Fault

To resolve this issue, reset your boiler. If it still does not operate, and your system is under warranty, contact your manufacturer.

Ideal Boiler C Fault Codes

C2 – Boiler Chip Card Fault

 Try to reset your boiler

C0 – Central Heating Signal Problem

Ask a certified engineer to check the thermostat and circulation in the radiator

Other Ideal Boiler Faults:

No Display

 If you see this message, it means the boiler display is blank. Make sure the mains supply is on and that no trips have been made in the consumer unit.

Noisy Operation

Problems like excessive boiling often occur with central heating. Clicking or humming can indicate problems such as high pressure or loose parts. To resolve this issue, try re-compressing the boiler or inspecting the system for loose components. If one of these measures does not solve the problem, seek help from the repair team.

Fault Code 0

Ideal oiler status 0 means that the oiler is in standby mode waiting for hot water or central heating needs.

If you see any fault code flashing on your Ideal boiler it is better to call an engineer. The diagnosis will then tell you if it is better to get it repaired or to get it replaced. If you want to check if your Boiler is under warranty, we will help you with it, Call us

If you want to know more about Ideal Boilers, click here

2.Baxi Gas Boiler Error Codes:

The most common Baxi Gas Boiler error codes are explained below. To know more click the link here.  The source: Baxi Error codes

1. BAXI 200 COMBI / BAXI 400 COMBI error codes

H.01 - .00

Temporary Fault - Temporary loss of communication between the gas valve and boiler board. Fault in air/gas unit.

Loose connection to the gas valve.

H.01 - .05

Temporary Fault - Maximum difference between the flow and return temperature exceeded. Non-existent or insufficient circulation. Sensor error.

H.01 - .08

Temporary Fault - Flow temperature increasing too fast in heating mode. Non-existent or insufficient circulation.
Sensor error.

H.01 - .14

Temporary Fault - Maximum flow temperature value exceeded. Non-existent or insufficient circulation. Non-existent or insufficient circulation.

H.01 - .18

Temporary Fault - No circulation of water. Non-existent or insufficient circulation. Sensor error.

H.01 - .21

Temporary Fault - Flow temperature increasing too fast in DHW mode. Non-existent or insufficient circulation. Sensor error.

H.02 - .02

Temporary Fault - No input of parameters C1/C2. PCB not configured.

H.02 - .03

Temporary Fault- Incorrect configuration settings C1/C2

H.02 - .04

Temporary Fault - Parameter error. Incorrect parameters.

H.02 - .06

Temporary Fault - System water pressure. Water leak on the boiler. Water leak on the system.

H.03 -.00

Temporary Fault - Communication error with NTC flue sensor. Sensor not, or badly connected. Bad connection. Sensor fault.

H.03 -.01

Temporary Fault - Communication error with the HMI PCB. HMI is not connected.

H.03 -.02

Temporary Fault - No flame during operation. No ionization current.

E.00 - .04

Permanent Fault - Return temperature sensor open-circuit. Sensor not or badly connected. Bad connection. Sensor fault

E.00 - .05

Permanent Fault - Return temperature sensor open-circuit. Sensor not or badly connected. Bad connection. Sensor fault.

E.01 - .02

Permanent Fault - Temperature measured by return sensor greater than flow sensor. Bad connection. Sensor fault. Sensor not or badly connected.

E.01 - .04

Permanent Fault - Loss of flame detected 5 times in 24 hours (With burner on). No ionization current.

E.01 - .11

Permanent Fault Requiring Reset - Incorrect fan speed. External draught over the boiler. Defective gas/air unit

E.01 - .12

Permanent Fault Requiring Reset - Temperature measured by return sensor greater than flow temperature.

E.01 - .17

Permanent Fault Requiring Reset - No circulation. Sensor not or badly connected. Sensor fault.

E.01 - .20

Permanent Fault - Maximum flue gas temperature value reached (>140 Deg C). No circulation. Sensor fault.

E.02 - .00

Permanent Fault - Boiler reset in progress. The reset button has been pressed.

E.02 - .07

No or low system water pressure. Low system pressure (less than 0.5bar) boiler will not function.

E.02 - .16

Permanent Fault - Onboard CSU time-out. Check PCB for damage.

E.02 - .17

Permanent Fault - Permanent loss of communication between the gas valve and boiler PCB. Fault in air/gas unit. Loose connection to the gas valve.

E.02 - .47

Permanent Fault - Connection to external device unsuccessful. Check wiring to the external device

E.02 - .48

Permanent Fault - Configuration to external device unsuccessful. Check to pair to external.

E.04 - .00

Permanent Fault - Gas valve fault. Gas valve not detected.

E.04 - .01

Permanent Fault - Flow temperature sensor short-circuited. Sensor not or badly connected. Bad connection. Sensor fault.

E.04 - .02

Permanent Fault - Flow temperature sensor open-circuited. Sensor not or badly connected. Bad connection. Sensor fault.

E.04 - .03

Permanent Fault - Critical flow temperature reached. Non-existent or insufficient circulation.

E.04 - .04

Permanent Fault - Flue temperature sensor short-circuited. Sensor not or badly connected. Bad connection. Sensor fault.

E.04 - .05

Permanent Fault - Flue temperature sensor open-circuited. Sensor not or badly connected. Bad connection. Sensor fault.

E.04 - .06

Permanent Fault - Critical flue gas temperature value reached. No circulation. Sensor fault.

E.04 - .08

Permanent Fault - Maximum safe temperature value reached. (Safety thermostat open-circuited). No circulation. Sensor not or badly connected. Bad connection. Sensor fault.

E.04 - .10

Light failure (could be a gas supply issue).

E.04 - .12

Permanent Fault - False flame signal. Short-term fluctuation of the mains. Ionization current presents even though there is no flame. The burner remains very hot (CO2 too high). Defective gas/air unit.

E.04 - .13

Permanent Fault - Fan rotor blocked. Fan seized. Wiring to fan damaged.

E.04 - .17

Permanent Fault - Problem with the gas valve. Defective gas/air unit.

2. BAXI PLATINUM+ 40KW error codes

E20 error code

Central heating NTC fault

E28 error code

Flue NTC fault, air pressure switch fault, blocked flue, blocked condensate or wiring fault.

E50 error code

Hot water NTC fault

E110 error code

E110 safety thermostat operated

E119 error code

Water pressure switch not operated

E125 error code

Circulation fault (primary circuit)

E130 error code

Flue NTC operated

E133 error code

Interruption of gas supply or flame failure

E160 error code

Fan or fan wiring Fault

E193 error code

Pre-circulation fault

3. BAXI 600 COMBI / BAXI 800 COMBI error code

E09 error code

Gas valve connection cable.

E10 error code

External probe fault.

E12 error code

Differential water flow switch fault (still open).

E13 error code

Differential water flow switch fault (still closed).

E15 error code

Gas valve command fault.

E20 error code

Central heating NTC fault.

E28 error code

Flue NTC fault.

E40 error code

Central heating returns NTC fault.

E50 error code

DHW NTC sensor fault (tank boiler) (s.c.) OR DHW NTC sensor fault (tank boiler) (o.c.).

E83/E84/E85/E86/E87 error code

No communication.

E109 error code

Pre-circulation fault.

E110 error code

i) Boiler max temperature exceeded for gradient (probable pump jammed or air in the circuit). OR ii) Boiler max temperature exceeded for overtemperature (probable pump jammed or air in the circuit). OR iii) Safety thermostat sensor tripped.

E118 error code

Primary system water pressure too low (< 0.5 bar).

E125 error code

Circulation fault (primary).

E128 error code

Frequent flame failure (12 times).

E129 error code

Safety error for frequent loss of flame with max correction during the ignition during Calibration Function.

E130 error code

Flue thermostat sensor tripped (lockout).

E133 error code

Light failure (could be a gas supply issue).

E134 error code

Elapsed time gas valve open without gas (short request in a short period)

E135 error code

Interruption of gas supply (internal error).

E154 error code

Flow/return sensor temperature test.

E160 error code

Fan or fan wiring fault.

E163 error code

Domestic Hot Water NTC sensor fault (s.c.) OR Domestic Hot Water NTC sensor fault (o.c.).

E270 error code

Circulation fault (dry fire).

E317 error code

Wrong power supply electrical frequency (Hz).

E321 error code

Hot water NTC fault.

E384 error code

False flame.

E385 error code

Under voltage.

E430 error code

Water pressure temporary test

E430 + Flame 'crossed' error code

The water pressure test failed.

4. BAXI 600 HEAT / MAIN ECO COMPACT HEAT

1 flash green error

Maximum flow temperature exceeded, Flow temperature rise rate too high, Excessive difference between, flow and return temperature

2 flashes green error

BL terminals on User Interaction, Controller are open circuit

3 flashes green error

No flame detected during operation

4 flashes green error

Bad connection or wiring fault, Internal communication fault

5 flashes green error

Parameter error or faulty PU, Configuration error or PCB fault

6 flashes green error

possible fault Internal fault in combustion control unit

1 flash red error

Bad connection to flow or return temperature sensor

2 flashes red error

Over-temperature thermostat on heat exchanger activated, No water flow through heat exchanger, PCB over-temperature condition, Flue fault resulting in, Recirculation or activation of airpressure switch (if fitted)

3 flashes red error

No ignition, No flame detected following ignition, False flame signal detected

4 flashes red error

Fan calibration error, Fan failure

5 flashes red error

Bad connection to PU, Parameter error or faulty PU

6 flashes red error

possible fault Bad connection or wiring fault, Parameter error

5. BAXI 600 SYSTEM / BAXI 800 SYSTEM / BAXI 600 LPG error code

E09 error code

Gas valve connection cable

E15 error code

Gas valve fault

E20 error code

Central heating NTC fault

E28 error code

Flue NTC fault

E40 error code

Central heating return NTC fault

E83 error code

Communication error

E109 error code

Pre-circulation fault

E110 error code

Safety thermostat operated

E118 error code

Primary system water pressure too low

E125 error code

Circulation fault (primary)

E128 error code

Flame failure

E130 error code

Flue NTC operated

E133 error code

Interruption of gas supply or flame failure

E135 error code

Interruption of gas supply (internal error)

E135 error code

Interruption of gas supply (internal error)

E154 error code

Flow/ return sensor temperature test

E160 error code

Fan or fan wiring fault

E270 error code

Circulation fault (Dry fire)

E321 error code

Hot water NTC fault 

E384 error code

False flame

If you want to know more about Baxi Boilers, click here

3. Worcester Gas Boiler Fault Codes

Lock Error

Boiler display blinks with warning triangle and error code. At the same time, the (static) cause code will also be displayed. Manual intervention is required (press the reset button on the front panel of the boiler) after the fault has been eliminated.

Blocking error

the boiler will stop working without any error data being displayed. The cause code, in the info menu, can be accessed by pressing the back key/button. The condition will clear automatically when the relevant fault disappears, e.g. wait for an area to cool. In some cases, the blocking error has a certain amount of time before switching to the blocking condition.

Fault error

Alphanumeric code indicating the error group.

Cause error

Three-digit number. While a blocking error (or normal operating state) occurs, it is not displayed, but is accessible in the info menu via the back key/button. During a lock failure, the cause code will flash on the display.

Maintenance codes

 
H11

Hot water can still be delivered but with less control due to a faulty hot water outlet sensor.

H13

A time, ranging from 1 to 72 months, was set in the Service interval function, and that time has now expired. This feature can be enabled or disabled via the 2.5F menu (1 to 72); a 0 disables the function.

- Worcester Bosch fault codes: locking errors

Locking errors -9A: HCM (Heat control module)
Cause code: 362
Possible cause Incorrect HCM fitted

Locking errors -9U: HCM (Heat control module)
Cause code: 233
Possible cause The code plug causing problems (faulty or not connected)

Locking errors - B7: Internal error
Cause code: 257
Possible cause: Replace control board

Locking errors - C6: Fan problem
Cause code: 215/216
Possible cause: Running too fast/Running too slow

Locking errors C7: Fan problem
Cause code: 214
Possible cause: Fan not running

Locking errors- C7: No airflow after a defined period of time 
Cause code: 217
Possible cause: Fan not running or airflow blocked

Locking errors- D1: Return sensor error
Cause code: 240/241
Possible cause: Sensor wet or damaged /Sensor disconnected or damaged (the boiler will block for 300 seconds before this condition)

Locking errors- D1: Return temperature too high
Cause code: 286
Possible cause: Boiler overheat

Locking errors- E2: Flow sensor short/open circuit
Cause code: 222/223
Possible cause: Flow sensor shorted or damaged

Locking errors- E5: Flow temperature too high
Cause code: 218
Possible cause: Primary flow sensor overheated

Locking errors- E5: Primary flow sensor has exceeded 110°C
Cause code: 332
Possible cause: Primary flow sensor overheated

Locking errors- E9: Safety sensor temperature too high
Cause code: 219
Possible cause: The main heat exchanger has overheated. Maximum temperature 105°C

Locking errors- E9: Safety sensor short/open circuit
Cause code: 220/221
Possible cause: Maximum temperature sensor on the main heat exchanger has failed/ not recognized

Locking errors- E9: Max temperature thermostat activated
Cause code: 224
Possible cause: Flue gas thermostat overheat

Locking errors- EA: No flame detected after ignition
Cause code: 227
Possible cause: Failure of four ignition attempts. The boiler waits 30 seconds before another attempt is made

Locking errors- EA: Loss of flame signal during operation
Cause code: 229
Possible cause: This could be caused by:
– Moisture in the sump, due to a blocked sump/condensate trap
– A strong wind into the flue

Locking errors- EA: Gas valve error
Cause code: 234
Possible cause: Gas valve coil disconnected

Locking errors- EA: Ignition timing error
Cause code: 261
Possible cause: Flame not established during the first 4 seconds ignition period

Locking errors- EA: Too many short burner starts without confirmation
Cause code: 338
Possible cause: There is an error where the pump is not detecting water – check pressure gauge and repressurise to 1 bar

- Worcester Bosch fault codes: blocking errors

Locking errors- A1: Pump stuck or running in air
Cause code: 281
Possible cause: Little or no water in the system – check pressure gauge and repressurise to 1 bar

Locking errors- C1: Airflow stopped during operation 
Cause code: 264
Possible cause:  Fan has stopped

Locking errors- EA: No ionisation detected after ignition 
Cause code: 227
Possible cause:  No flame is detected. The boiler will block during 4 attempts before going to Locking fault

Locking errors- EF: Central heating, boil detect – Large delta T despite minimum burner
Cause code: 349
Possible cause:  The boiler is operating at minimum burner load and there is a greater than 18°C Flow & Return temperature difference

Locking errors- No code: Safety or flow temperature rises too fast 
Cause code: 212
Possible cause: Air lock or reduced water content – check pressure gauge and repressurise to 1 bar

Locking errors- No code: Temperature difference between supply and return exceeding limit 
Cause code: 213
Possible cause: Air lock or reduced water content – check pressure gauge and repressurise to 1 bar

Locking errors- No code: No temperature rise after burner starts
Cause code:  260
Possible cause: Sensor disconnected or no water content – check pressure gauge and repressurise to 1 bar

If you want to know more about Worcester Boiler, click here

4. Vokera Gas Boiler Fault Codes

_St fault code

Autostop

_CL fault code

Call for service

A01 fault code

Ignition failure flame not sensed – internal fault

A01 fault code

Limit thermostat fault

A03 fault code

Fan fault

A04 fault code

Insufficient system water pressure

A06 fault code

Domestic how water (DHW) thermistor fault

A07 fault code

Primary flow thermistor fault – temperature of the water is too high

A08 fault code

Return thermistor fault – water temperature too high

A09 fault code

Flue thermistor or flue thermistor counter fault

A11 fault code

False flame

A77 fault code

Low-temperature thermostat fault

ADJ fault code

Calibration

ACO fault code

Service operation

N/A fault code

Flame on

P fault code

Preheating function active

P Blinking fault code

Preheating function running

Hours 

Stand-by

-
Off

01 fault code

Failure to ignite

02 fault code

Overheat

03 fault code

Problem with fan/flue

04 fault code

Insufficient water pressure

05 fault code

Reset as described for code 01

06 fault code

Hot water thermistor open circuit

07 fault code

Primary thermistor open circuit

Vokera Mynute Boiler Error Codes 

AL10, AL20, AL21, AL26, AL28, AL34 fault code

Try resetting the boiler, if the fault reoccurs you need to contact a heating engineer

AL40 fault code

Check the system’s pressure and refill if necessary. Reset the boiler, if the fault reoccurs then you need to contact a heating engineer

AL41 fault code

Check system pressure – refill if necessary. If the fault reoccurs, contact a heating engineer

AL52, AL55, AL60, AL71,AL73, AL74, AL79 fault code

Contact a heating engineer

AL74, AL79 fault code

Reset the boiler. If the fault reoccurs, contact a heating engineer

Vokera Evolve Combi Boiler Error Codes | Vokera Evolve System Boiler Error Codes 

E10 fault code

Flame lockout

E011 fault code

Extraneous flame

E020 fault code

Limit thermostat

E030 fault code

Fan fault

E040 fault code

Water transducer – check the system water pressure

E041 fault code

Water transducer – check the system water pressure

E042 fault code

Water transducer fault

E060 fault code

Domestic hot water probe fault

4070 fault code

Fault flow sensor over temperature – flow sensor flow/return line probe differential alarm

E077 fault code

Main zone water thermostat

E080 fault code

Error with return line probe – over-temperature outlet or differential alarm

E090 fault code

Flue gases over-temperature probe

E091 fault code

Clean primary heat exchanger

E021, E022, E023, E024, E067. E088, E097 fault code

Iono alarm 

E085, E094, E095 fault code

Combustion fault/high CO

E058 fault code

Main voltage error

E065 fault code

Current modulation alarm

E086 fault code

Obstruction fumes alarm

If you want to know more about Vokera Boilers, click here

Glow worm Boiler Faults

Glow-worm Betacom Boiler

Fault: Red LED On

Lockout – low water pressure

Fault: Red LED flashing

Overheat 

Fault: Yellow LED flashing

Turn the domestic hot water (DHW) control knob into the temperature range and turn the central heating (CH) temperature control knob into power (reset position) 

Fault: Green LED off

No power to the boiler

Glow-worm Betacom4 / Ultracom3 cxi / sxi / 35Boiler

F00 / F10 / F71 Fault Code

Flow heating temperature sensor fault

F01 / F11 Fault Code

Return heating temperature sensor fault

F20 Fault Code

Overheating 

F9 / F22 Fault Code

Low water pressure

F26 / F77 Fault Code

Fault in gas valve

F27 / F16 Fault Code

Flame detection fault

F28 / F1 / F4 Fault Code

Ignition fault

F29 Fault Code

Loss of flame during operation

F32 Fault Code

Incorrect air pressure

F49 Fault Code

EBUS voltage fault

F61 / F62 / F63 / F64 / F65 / F67 Fault Code

Fault in the main board

F68 Fault Code

Fluctuation of flame signal

F70 Fault Code

User interface incompatible with the main board

F72 / F84 Fault Code

Permanent temperature difference between flow and return heating sensors

F73 / F74 Fault Code

Heating circuit pressure sensor fault

F76 /F83 Fault Code

Thermal fuse fault

F85 Fault Code

Flow and Return heating sensor fault

All Glowworm Boilers

ERR / F12 / F18 Fault Code

User interface fault

F2 Fault Code

Fan/APS

F5 Fault Code

Overheat Fault

F6 Fault Code

Central heating flow thermistor

F7 Fault Code

Domestic hot water thermistor

F8 Fault Code

Tank thermistor fault

F10 Fault Code

Central return flow thermistor

F11 Fault Code

Main board connection fault

F25 / F23 Fault Code

Generic Error
 

Potterton Boiler Fault Codes

Potterton Promax Combi, System Error Codes

Potterton Promax Ultra, Gold/Titanium Combi & System Boiler Error Codes

If your Gas Boiler is not working or you need a Gas Boiler service or Need a New Gas Boiler, Dublin's biggest plumbing and electrical company is one call away. Call or email Stillorgan Gas, Plumbing & Electrical now.