Boiler on the Blink!
Get the warmth back in your home! Use our Boiler Fault Codes Guide
If your boiler develops a problem or error, it often displays boiler fault codes to help you diagnose it on the front panel. These can be confusing as they appear as a variety of different numbers and letters, specific to the boiler itself and the issue. Here at 24/7 Emergency Plumbing Contractors, we want to make sure that our customers have as much information and assistance as possible, so below we have developed a list of all the boiler fault codes which could appear on a Worcester Bosch, Vaillant, Baxi or Ideal Heating boiler, which we install & maintain. Please rest assured faults and errors are a rare occurrence with today’s modern and reliable boilers.
If your boiler is showing a fault, contact us to arrange a repair with a Gas Safe registered engineer. We offer an emergency repair service, which is available 24/7 one of our engineers will never be far away. We know that a boiler breakdown can be frustrating, so at 24/7 Emergency Plumbing Contractors we are here to help, no matter how small the issue.
Avoid costly repair bills, sign up to one of our boiler care plans today!
Same Day Boiler Repairs In Milton Keynes
Local Gas Safe engineers, A Phone Call Away
Identify Boiler Fault Codes
9A | Boiler has been fitted with incorrect Heat Control Module (HTM). |
9U | The code plug could be faulty or not properly connected. |
B7 | You need to replace the control board. |
C6 | The system is running too fast or too slow. |
C7 | Fan is not running or the airflow could be blocked. |
D1 | Sensor could be wet, damaged or disconnected. The boiler will block for 300 seconds. |
D1 | Boiler is overheating. |
E2 | The Flow sensor has shorted, is damaged or disconnected. |
E5 | The primary flow sensor has overheated. |
E9 | The main heat exchanger has overheated as the main temperature is 150 degrees. |
E9 | Maximum temperature sensor on the main heat exchanger cannot be recognised or has failed. |
E9 | The flue gas thermostat has overheated. |
EA | Failure after four ignition attempts. The boiler will wait 30 seconds before another attempt is made. |
EA | A flame has been extinguished due to either moisture in the sump, a blocked sump or strong wind in the flue. |
EA | Gas valve coil has been disconnected. |
EA | Flame has not extinguished within first 4 seconds of ignition. |
EA | There is an error as the pump is not detecting water. Check the pressure gauge and re-pressurise to 1 bar. |
C0 | BCC Activation Fault. |
C2 | BCC Fault. |
F1 | Low Water Pressure. |
F2 | Flame Loss. |
F3 | Fan Fault. |
F4 | Flow Thermistor. |
F5 | Return Thermistor. |
F6 | Outside Sensor Failure. |
F7 | Low Mains Voltage. |
F9 | Unconfigured PCB. |
L1 | Flow Temperature Overheat or No Water Flow. |
L2 | Flame Loss. |
L5 | 5 Boiler Resets in 15 Minutes. |
L6 | False Flame Lockout. |
0 | The boiler is in standby mode awaiting either a central heating call or hot water demand. |
C | The boiler has a call for central heating but the appliance has reached the desired temperature set on the boiler. |
C | The boiler is in operating in central heating mode. |
D | The boiler has a call for hot water but the appliance has reached the desired temperature set on the boiler. |
D | The boiler is operating in hot water mode. |
F | The boiler is operating in frost mode. |
EcoMax Pro 18/28E Fault Code | Possible Cause |
F.1 | Lack of gas, a fault with the ignition or flue, or you may need to adjust the gas valve or replace a defective electrode lead. |
F.4 | Ignition fault. |
F.5 | The system has suffered a fault due to overheating. |
F.6 | Your flow NTC (temperature sensor) has developed a fault. |
F.17 | Check the polarity of your system |
F.21 | The pump could have failed, over run or there could be an issue with the air lock. |
Turbomax Plus 824/8E | Possible Cause |
F.00 N | The flow NTC (Negative Temperature Coefficient Thermostat) cable is either defective or broken and needs replacing. |
F.01 | The flow NTC (Negative Temperature Coefficient Thermostat) cable is either defective or broken and needs replacing. |
F.10 | Short circuit with the NTC. |
F.13 | Short circuit with the NTC. |
F.20 | Your boiler has exceeded the maximum temperature and needs to cool. |
F.22 | There is dry fire, low water in the system which is overheating. You may have a defective pump or pump lead. |
F.24 | Your pump could be obstructed, at low capacity or there could be trapped air. The pressure of your system could be too low. |
F.28 | There is insufficient gas, a defective electrode, ignition lead or electronic ignitor. |
F.29 | Your flame or pilot light has gone out. Check your flue duck or gas supply to see if there is a problem. |
F.60 | Your cable loom which connects your gas valve may have short circuited. You could have a defective gas valve or electronic control system. |
F.61 | Your cable loom which connects your gas valve may have short circuited. You could have a defective gas valve or electronic control system. |
F.62 | Your boiler has exceeded the maximum temperature and needs to cool down. |
F.63 | This is an electronic fault within your system. An error with your EEPROM (electrically erasable programmable read-only memory.) |
F.64 | Your flow or backflow NTC has suffered a short circuit or an electronic fault. |
F.65 | Electronic system temperature too high, potentially due to an external heat source or electrical fault. |
F.67 | Electronic fault in flame system. |
E09 | Gas valve connection cable |
E15 | Gas valve fault |
E20 | Central heating NTC *Negative Temperature Coefficient fault |
E28 | Flue fault |
E40 | Central heating return fault |
E55 | Calibration required |
E109 | Pre-circulation fault |
E110 | Safety thermostat operated |
E117 | Water pressure too high |
E118 | Water pressure too low |
E125 | Circulation fault (primary) |
E128 | Flame failure |
E130 | Flue NCS operated |
E133 | Gas supply interrupted or flame ignite failure |
E134 | Gas valve open without gas – time elapsed |
E135 | Interruption of gas supply |
E154 | Flow/return sensor temperature test |
E160 | Fan fault |
E270 | Circulation fault (dry fire) |
E321 | Hot water NTC fault |
E384 | False flame |
| E09 | Gas valve wiring fault |
| E10 | Outdoor sensor error |
| E15 | Gas valve connection fault |
| E20 | Central heating thermistor sensor fault |
| E28 | Flue thermistor fault |
| E40 | Central heating return thermistor fault |
| E50 | Hot water sensor fault |
| E53 | Flue obstruction |
| E55 | Calibration issue |
| E78 | Water pressure sensor fault |
| E92 | Combustion test alarm |
| E109 | Poor circulation |
| E110 | Boiler overheat tripped |
| E117 | System pressure too high |
| E118 | System pressure low |
| E119 | System pressure low |
| E125 | Primary water circulation fault |
| E128 | Loss of flame |
| E129 | Loss of flame |
| E130 | Flue thermostat sensor tripped (lockout) |
| E131 | Flue overheat lockout |
| E133 | Ignition fault |
| E135 | Internal error |
| E151 | PCB fault |
| E152 | PCB fault |
| E154 | Primary flow fault |
| E160 | Fan fault |
| E161 | Fan fault |
| E164 | Hot water sensor error |
| E167 | PCB fault |
| E168 | PCB lockout |
| E193 | Circulation issue |
| E270 | Dry fire |
| E317 | Wrong power supply |
| E321 | Hot water thermistor fault |
| E384 | Flame detected when gas valve off |
| E385 | Low voltage |
Boiler Make & Associated Error Codes
ATAG – 133
Baxi – E133 or E28
Glow-worm – F1, F4, F28 or F29
Main – E133
Potterton – E133
Vaillant – F28 or F29
Viessmann – F4EE
Worcester Bosch – EA229 D5
Ideal L2
“Ok I’ve identified the issue, now how do I fix it?”
First things first, you need to find the part of the pipe that has the blockage so you know you’re thawing out the right area. To help you, there will often be a bend or dip there in the pipe. There are several different methods you can use to thaw it out:
* applying a hot water bottle to the area
* applying a microwaveable heating pack
* applying a warm cloth
* pouring hot water over it using a watering can. (Caution – do not use boiling water as this could melt the plastic pipe!)
Once you have unfrozen the pipe, your boiler should restart automatically, however you might need to reset it. Check the manual to be sure.
“Can I prevent this from happening again?”
Yes, there are a few things you can do:
* covering the condensate pipe with foam insulation
* leaving your heating on overnight
* turning your thermostat up however your radiators may then be too hot
“I need help!”
If you would like help unfreezing or insulating your boiler’s condensate pipe, contact 24/7 Emergency Plumbing Contractors now and we will send out an engineer in no time at all.
These fault codes are designed to help an emergency boiler repair engineer diagnose the problem with your boiler.
Without these fault codes, they’d be aimlessly fault finding, which would end up taking them much longer than they should and costing you much more than it should.
Working on gas appliances is not a DIY job, and could cost lives if done incorrectly. Always ask to see the engineers Gas Safe credentials.
