Sime Combi Boiler Error Codes Over the years, Sime boilers have made their way into several UK households where they are relied upon for domestic hot water supply and central heating. And like any other boiler brand, these Sime boilers are also designed to display error codes when they have an internal issue.
Sime Boiler Error Code Solutions
| Fault code | Description |
| AL02 | Low water pressure in the system |
How to solve AL 02 Sime error code?
Restore pressure
If your boiler pressure is low, you’ll see the bars on the pressure gauge going down (below the standard pressure). In this case, we advise referring back to the boiler manual to learn how to re-pressurise your boiler; the manual includes step by step instructions to help you.
Once you’ve re-pressurised your boiler, it’s time to give it a quick reset. Most boilers will automatically reset, and the error code will disappear once you have done this.
Check for any leaks in the system
If you have attempted to repressurise your boiler already and still notice a drop in your boiler pressure, then you will need to get advice from a Gas Safe Engineer and ask them to come and check for leaks. If you have a leak then it will usually require them to reseal or potentially re-pipe your system where necessary.
| Fault code | Description |
| AL03 | High water pressure in the system |
How to solve AL 03 Sime error code?
This is a job for the heating engineer, they’ll empty the system via the drain valve on the Hydraulic assembly to bring the pressure to approximately 1.2 bar.
| Fault code | Description |
| AL04 | Domestic hot water sensor (SS) fault |
How to solve AL 04 Sime error code?
To solve this problem the heating engineer will check connections and replace the sensor.
| Fault code | Description |
| AL05 | Delivery sensor (SM) fault |
How to solve AL 05 Sime error code?
The heating engineer will check connections and replace the sensor to solve this issue.
| Fault code | Description |
| AL06 | No flame detection |
How to solve AL 06 Sime error code?
The heating engineer will perform the following;
- Check the integrity of the electrode and
- Check that it is not grounded
- Check gas availability and pressure
- Check the operation of the gas valve
| Fault code | Description |
| AL07 | Safety thermostat (TS) intervention |
How to solve AL 07 Sime error code?
Another job for the heating engineer-
- Check the sensor or thermostat connections
- Deaerate the system
- Check the bleed valve
- Replace the sensor or the thermostat
- Check that the pump impeller is not blocked
| Fault code | Description |
| AL08 | Fault in the flame detection circuit |
How to solve AL 08 Sime error code?
The heating engineer will;
- Check the integrity of the electrode and check that it is not grounded
- Check gas availability and pressure
- Check the operation of the gas valve
| Fault code | Description |
| AL09 | No water circulating in the system |
How to solve AL 09 Sime error code?
You must call the heating engineer to;
- Check the rotation of the system pump impeller
- Check the electrical connections
- Replace the pump (if needed)
| Fault code | Description |
| AL10 | Auxiliary sensor fault |
How to solve AL 10 Sime error code?
- Check the hydraulic configuration in the boiler
- Check the electrical connection
| Fault code | Description |
| AL11 | Auxiliary sensor fault |
How to solve AL 11 Sime error code?
Check the electrical connection
| Fault code | Description |
| AL12 | Incorrect configuration of the open/sealed chamber |
How to solve AL 12 Sime error code?
Set the parameter tS 0.4 (Combustion configuration) to 0
| Fault code | Description |
| AL13 | Exhaust sensor (SF) intervention |
How to solve AL 13 Sime error code?
- Replace the smoke probe
- Contact the Technical Assistance Centre
| Fault code | Description |
| AL14 | Exhaust sensor (SF) fault |
How to solve AL 14 Sime error code?
- Replace the smoke probe
- Check the electrical connection of the smoke probe, if the problem is not resolved, contact the Assistance Centre
| Fault code | Description |
| AL15 | Fan check cable disconnected |
How to solve AL 15 Sime error code?
Check the connection cable between the fan and the board
| Fault code | Description |
| AL18 | Condensate level fault |
How to solve AL 18 Sime error code?
- Check for any clogging in the pipe which takes the condensate to the siphon
- Check that the siphon is not clogged
| Fault code | Description |
| AL28 | Maximum number of consecutive resets reached (6) |
How to solve AL 28 Sime error code?
- Contact the Technical Assistance Centre AL 37 Fault due to low network voltage.
- Check with tester
- Contact network provider (ENEL)
| Fault code | Description |
| AL40 | Incorrect supply frequency detected |
How to solve AL 40 Sime error code?
Contact network provider (ENEL)
| Fault code | Description |
| AL41 | Flame loss more than 6 consecutive times |
How to solve AL 41 Sime error code?
- Check the detection electrode
- Check the gas supply (open valve)
- Check mains gas pressure
| Fault code | Description |
| AL42 | Button fault |
How to solve AL 42 Sime error code?
Check that buttons are working
| Fault code | Description |
| AL43 | Open Therm communication fault |
How to solve AL 43 Sime error code?
Check the electrical connection of the remote control
| Fault code | Description |
| AL62 | Self-calibrating procedure is required |
How to solve AL 62 Sime error code?
Carry out the self-calibrating procedure
| Fault code | Description |
| AL72 | Incorrect positioning of the delivery sensor |
How to solve AL 72 Sime error code?
Check that the delivery sensor is attached to the delivery pipe
| Fault code | Description |
| AL81 | Block due to combustion during start-up |
How to solve AL 81 Sime error code?
- Check for blockage in flue
- Bleed the air from the gas circuit
| Fault code | Description |
| AL83 | Block due to combustion during start-up |
How to solve AL 83 Sime error code?
Check for blockage in the flue
| Fault code | Description |
| AL96 | Lockout due to flue (exhaust) blockage |
How to solve AL 96 Sime error code?
Check for blockage in flue