Worcester Bosch Greenstar Ri Boilers

12 fault codes documented

2 pulses

2 pulses (blue light) — Flue pressure switch fault

The blue indicator light shows 2 pulses, signifying a fault with the flue pressure switch. This often means there's an issue with the flue's ability to clear combustion products.

5 pulses

5 pulses (blue light) — Volatile lockout (sensor, fan, or code plug issue)

The blue indicator light displays 5 pulses, indicating a volatile lockout related to a sensor, the fan, or the code plug. This is a general electronic fault.

Burner lights, then goes out

Burner lights then goes out — Flue problem or combustion issue

The boiler's burner ignites successfully but then quickly extinguishes, failing to provide continuous heat for either hot water or central heating.

Fast flash

Fast flash (blue) — Heat exchanger overheat

The boiler's blue indicator light flashes quickly, indicating that the heat exchanger has overheated. This is a critical safety shutdown.

Light on, no operation

Blue light on, but boiler not operating during demand — No heat or hot water

The blue indicator light is on, indicating power, but the boiler does not start heating when there is a demand for central heating or hot water.

No CH, HW OK

No Central Heating but Hot Water OK — External control fault

The boiler provides hot water normally, but the central heating system does not turn on or heat up. This usually points to an issue outside the boiler itself.

No HW or CH demand

No Hot Water or Central Heating demand — Boiler not receiving call for heat

Neither hot water nor central heating is being produced, and the boiler is not responding to any calls for heat. This indicates the boiler isn't receiving a signal to operate.

No HW, CH OK

No Hot Water but Central Heating OK — External control fault

The boiler heats the central heating radiators normally, but no hot water is available for taps or showers. This typically indicates a problem with external components.

No light

No light — No power to boiler

The blue central indicator light is off, meaning there is no electrical power reaching the boiler or its control components.

Noisy/Overheat

Boiler noisy or going to overheat — Circulation or pump issue

The boiler makes excessive noise or frequently reaches an overheat condition, indicating a problem with water circulation or the pump.

Slow flash (off to on)

Slow flash (blue, normally off, flashes on) — Ignition lockout

The boiler's blue indicator light flashes slowly from off to on, indicating an ignition lockout. This means the boiler failed to ignite the gas.

Slow flash (on to off)

Slow flash (blue, normally on, flashes off) — Flue overheat

The boiler's blue indicator light flashes slowly from on to off, signaling that the flue temperature is too high. This is a safety measure to prevent damage.