Glow Worm boilers vary by simple identification of problems with the help of Glow Worm boiler fault codes. Below are 2 tables, thanks to which you can not only determine the cause of the problem, but in some cases you could fix the problem yourself. The table has fault codes, description of problem, possible cause and suitable solution. These tables will become an indispensable manual for the owners of boilers of this brand. They will help with the accuracy to determine the problem and decide whether to contact the service center or call the repairman or you can fix a problem yourself.
| CODE | DESCRIPTION | POSSIBLE CAUSE |
|---|---|---|
| F1 | Ignition fault (lockout) Boiler failed to light | No gas |
| Insufficient gas | ||
| Incorrect gas valve adjustment Electrode Ignition lead defect Electronic igniter defective Check air inlet duct Check connections to igniter unit | ||
| F4 (error solution F4) | Ignition fault (lockout) Went out when lit | As F1 possible cause |
| F5 | Overheat fault | Overheat stat operated |
| Maximum temperature exceeded | ||
| Check thermistor connections | ||
| Air in system with thermistor at maximum setting | ||
| Faulty overheat stat connection | ||
| Check that pump is wired into appliance and not from programmer. | ||
| This would cause no pump overrun | ||
| F6 | Central heating flow thermistor fault | Thermistor cable defective/broken, thermistor faulty Check that thermistor attached correctly to pipe |
| F9 (error solution F9) | Water pressure sensor fault | Faulty sensor connection – check wiring |
| F10 | Central heating return thermistor fault | Thermistor cable defective/broken, thermistor faulty |
| Check that thermistor attached correctly to pipe | ||
| F11 | Main board connection fault | Check wiring between mainboard and user interface |
| F12 | User interface connection fault | |
| F13 | Main PCB connection fault | Check connections and wires |
| F14 | Central heating flow temperature is greater than 95C | System fault Possible pump failure |
| Check Thermistor on flow | ||
| F16 | Flame detection fault (flame presence for more than 5 seconds after burner stop) | Gas valve defective |
| F17 | Power supply is less than 170V | Check electrical supply / polarity |
| F18 | User interface fault | Faulty User Interface |
| F19 | Central heating thermistor unplugged | Check Thermistor connection |
| F20 | Software incompatibility | Incorrect user interface or Main PCB |
| F21 | Lack of water fault (pressure is less than 0.5bar) | System leak or faulty pressure sensor |
| F22 (error solution F22) | Upper water pressure (is greater than 2.7bar) | Filling device open |
| F24 | Central heating return temperature is greater than 90°C | System fault Possible pump failure |
| Check Thermistor on return | ||
| F25 (error solution F25) | Maximum temperature rise slope | Possible pump failure Air in system |
| F26 | Maximum delta temperature | Check Thermistor on return System – too restrictive |
| Fault codes | Description | Cause | Solution |
|---|---|---|---|
| F00 | Flow heating temperature sensor fault | Sensor open circuit | • Check the sensor’s connections. |
| F01 | Return heating temperature sensor fault | Return heating temperature sensor disconnected | • Check the wiring harness. |
| F10 | Flow heating temperature sensor fault | Sensor short-circuit | • Check the sensor. |
| F11 | Return heating temperature sensor fault | Return heating temperature sensor shorted. | |
| F20 | Overheating fault | Overheating safety device activated (97°C) | • Check the operation of the pump. |
| • Check the wiring harness. | |||
| • Check that the flow and return heating isolation valves are open. | |||
| F22 (error solution F22) | Water pressure of the installation (<0.3 bar) | Return water valve closed Pump disconnected Leak in the installation | • Fill the installation. |
| • Purge the installation. | |||
| • Check the pump connections. | |||
| • Check the flow and return heating sensor connections. | |||
| • Check that there are no leaks. | |||
| F23 | Maximum temperature difference reached between return and flow heating | Water circulation fault | • Check the flow and return heating sensor connection. |
| • Check the pump speed. | |||
| F24 | Water circulation fault | Malfunction of the pump (excessively rapid temperature increase) | • Check that the flow and return heating isolation valves are open. |
| F26 | Fault in gas valve motor. | Disconnected or defective cables | • Check the gas valve connections. |
| • Check the operation of the gas valve. | |||
| • Check the operation of the condensate pump (option). | |||
| F27 | Flame detection fault. | Abnormal flame detection | • Check the flame detection electrode. |
| • Check the main board. | |||
| • Check the igniter unit. | |||
| F28 | Ignition fault | No return gas / Insufficient gas flow Gas valve incorrectly adjusted Defective firing electrode and flame control / Defective igniter unit | • Check the return gas circuit (gas valve open). |
| • Check the observe the flame picture and check the C0 2 setting. | |||
| • Check the igniter unit connections. | |||
| F29 | Loss of flame during operation | • Check the state of the electrode (corrosion). | |
| F32 | Incorrect air pressure | Incorrect fan speed. | • Check the entire flue system. |
| • Check the fan’s electrical connections. | |||
| F49 | EBUS voltage fault | Fault in EBUS line | • Check that the eBus controls are fitted and wired correctly. |
| Short circuit in EBUS connector | |||
| F61 | Fault in the main board | Gas valve command fault | • Check the main boards connections. |
| F62 | Gas valve closure fault | • Check the main board. | |
| F63 | Fault in the main board memory | • Check the appliance DSN number is correct. | |
| F64 | Rapid fluctuation of return or flow heating sensor. | • Reset the appliance. | |
| F65 | Excessive main board temperature | ||
| F67 | Flame signal fault in the main board | ||
| F68 | Fluctuation of flame signal | No return gas / Insufficient gas flow Gas valve incorrectly adjusted Defective firing electrode and flame control / Defective igniter unit | • Check the return gas circuit (gas valve open). |
| • Check the observe the flame picture and check the C0 2 setting. | |||
| • Check the igniter unit connections. | |||
| • Check the state of the electrode (corrosion). | |||
| F70 | User interface incompatible with the main board | Incorrect product code | • Check that the appliance DSN code on the screen matches the product code of the nameplate (in the event of a fault and the appliance DSN does not appear, consult menu.d.93 reserved for the code). |
| • Check the boards reference. | |||
| F71 | Flow heating temperature sensor fault | Flow heating temperature sensor unclipped or defective (no temperature variation) | • Check the sensor connections. |
| • Make sure that the sensor is clipped to the tube. | |||
| F72 | Permanent temperature difference between flow and return heating sensors | Mismatch between the flow and return heating temperatures (permanent difference) | • Check temperature sensors connections. |
| • Replace faulty sensors. | |||
| F73 | Heating circuit pressure sensor fault | The sensor is shorted or disconnected. | • Check the sensor’s connections. |
| F74 | Heating circuit pressure sensor fault | Fault in pressure sensor | • Check the sensor. |
| F76 | Thermal fuse fault | Thermal fuse disconnected Defective thermal fuse | • Check the fuses connections. |
| • Replace the heat exchanger. | |||
| F 77 | Fault in gas valve motor. | Defective gas valve. | • Check the gas valve connections. |
| Defective condensate pump (option) | • Check the operation of the gas valve. | ||
| • Check the operation of the condensate pump (option). | |||
| F83 | No water in the installation : the temperature does not increase when the burner is lit | Return water valve closed Pump disconnected Leak in the installation | • Fill the installation. |
| • Purge the installation. | |||
| • Check the pump connections. | |||
| • Check the flow and return heating sensor connections. | |||
| • Check that there are no leaks. | |||
| F84 | Permanent temperature difference between flow and return heating sensors | Inverted or disconnected flow and return heating temperature sensors Defective temperature sensors | • Check temperature sensors connections. |
| • Replace faulty sensors. | |||
| F85 | Flow and return heating sensors fault | Flow and return heating temperature sensor connected to same tube | • Check temperature sensors connections. |
| F86 | Underfloor heating contact fault | Floor heating contact open Sensor disconnected or defective | • Check the sensor connections. |
| • Check that the sensor is connected to the main board and the shunt is removed. | |||
| Err | User interface fault | Defective user interface | • Check connection from user interface PCB to main PCB. |
| • Replace user interface. |