BoilerFaultCodes.com

Worcester Bosch 24si II Fault Codes

Combi Natural GasLPG 24 kW 2002-2005 Discontinued
GC Number: 47-108-11

Replaced by: Greenstar 24i

This boiler uses LED flash patterns

Count the flashes in one repeating group before the pause. That number is your fault code. Do not reset until you have noted it. How to read fault codes →

Most common fault codes

Burner on with no demand
Your boiler is firing up and staying on even when you haven't turned on your heating or hot water taps.
Gas Safe engineer required · £280-450
Flash 4 times per second
Your boiler has detected an internal communication or airflow issue that has caused it to shut down for safety.
Gas Safe engineer required · £120-350
Flash once per second
Your boiler has stopped working because it has failed to light or has detected a dangerous build-up of heat.
May be DIY safe · £120-450

All 10 fault codes

Code Severity Plain English
Burner on with no demand High Your boiler is firing up and staying on even when you haven't turned on your heating or hot water taps.
Flash 4 times per second High Your boiler has detected an internal communication or airflow issue that has caused it to shut down for safety.
Flash 8 times per second Medium Your boiler has been left in a service mode used for testing, meaning it is currently stuck running at a constant power level instead of operating normally.
Flash once per second High Your boiler has stopped working because it has failed to light or has detected a dangerous build-up of heat.
FLASHING FAST (five times a second) High Your boiler has detected a problem with how it vents waste gases or takes in fresh air, which is preventing it from firing up safely.
FLASHING SLOW (once per second) High Your boiler has stopped running because it failed to light properly or has become too hot, causing it to lock itself for safety.
LED 4 flash/second Medium Your boiler has detected an issue with the sensor that manages your hot water, meaning you will likely only have heating or very inconsistent water temperatures.
No CH function (DHW OK) Medium Your boiler is providing hot water normally, but is not receiving the signal to turn on the central heating due to a control or wiring issue.
No DHW function (CH OK) High Your boiler is providing central heating but is failing to detect when you turn on a hot tap, meaning you have no hot water.
No lights and no functions (with demand) High Your boiler has lost power completely and is unable to respond to any commands for heating or hot water because of an internal electrical failure.

Worcester Bosch 24si II is discontinued — time for a new one?

Parts for discontinued models can be hard to find and expensive. A new A-rated boiler could save you money on both repairs and energy bills.

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