Common Worcester Bosch Error Codes

This guide highlights the most common Worcester BOSCH error codes that show up on boilers and explain what they mean.

Common Worcester Bosch Error Codes

Before you begin to worry when a code appears on your Worcester Bosch Greenstar boiler, first try turning the boiler off and back on again to see whether it goes away. If a code still appears after the boiler has rebooted, here is a guide to what it might mean.

Fan Speed Error: C6 215

This indicates that the fan speed is too high.

Heat Control Module (HCM) Issues: 9A 362

This indicates that the HCM (Heat Control Module) is defective. A central heating engineer needs to be called to check it.

No Flame Signal Due To Blockage or Internal Leak: EA 227

This fault code on your boiler indicates an issue with the gas valve. It may need replacing, but it can also mean the gas ratio control valve needs adjusting. This code can also mean that the condensate discharge pipe is blocked or frozen.

Blocked Pump: A1 281

This code means the pump stuck or is running with air in the system. The heat control reset button can solve this issue. If not, call for help.

Minimum Burner Load: EF 349

The temperature sensor may need replacing.

Flow Temperature High: No Code 212

This fault code can indicate that the safety temperature limiter needs replacing.

Loss Of Ionisation Detected: EA 229

Connections need checking and the Worcester Bosch boiler should be reset.

Flow Temperature Sensor Too High: E5 218

If the flow temperature sensor is defective, it needs to be replaced.

Sensor Too High: 2964 B

The safety or flow temperature can be manually reset by turning the modulating gas valve in an anticlockwise direction.

Low Water Pressure: 1017 W

This can mean the water needs topping up.

Safety Sensor Code 226

If this code does not go away, the boiler may no longer be safe. Switch it off and call an engineer.

L&W Heating and Plumbing

Whatever your heating and plumbing needs  – from an annual gas safety check to brand-new boiler installation, L&W Heating and Plumbing can help: call us for more information.

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