The Worcester company is part of the Bosch Group. It has recently introduced a new combined gas boiler Worcester Greenstar i, which is characterized by enhanced productivity, A-class energy performance and many other useful features. And refer to the table below for Worcester boiler error codes.
Worcester Greenstar Highflow 440 boiler error codes
| Display Code: | Fault description: | Check, repair/replace as necessary: |
|---|---|---|
| A5 | Tank sensor fault | Tank sensor (8000 – 20000 ohms at room temperature). Wiring and connections to sensor. |
| A6 | Link fault | Check link 8 to 9 in connector ST3. |
| A7 | DHW sensor fault | DHW sensor (8000 – 20000 ohms at room temperature). Wiring and connections to sensor. |
| A8 | Module fail | Night set back module TR212E and/or Roomstat TR2. Wiring and connections between modules. |
| b1 | Code plug not detected | Code plug version, condition and fitting. If OK replace control board. |
| C1 | Fan speed too low | Fan harness and connections. Fan. Otherwise replace control board. |
| d3 | Terminals 8-9 not shorted at connector ST7 | Safety overheat thermostat for underfloor heating system (if fitted). |
| Otherwise fit link. | ||
| d5 | Condensate pump failed | Mains supply to condensate pump. Condensate Pump unit. |
| Continuity of all cables to pump unit. | ||
| d6 | Tank overheat | Tank sensor is correctly fixed to tank Wiring and connections to sensor. |
| E2 | CH flow sensor fault | CH flow sensor (8000 – 20000 ohms at room temperature). |
| Wiring and connections to sensor. | ||
| E9 (error solution E9) | Safety overheat device tripped | All air vented. |
| Water pressure above minimum. | ||
| Leaks or blockage. | ||
| Condition and attachment of CH flow sensor. | ||
| Pump and associated wiring/connections. | ||
| Connections and wiring to overheat thermostat devices. Otherwise replace control board. | ||
| EA | Flame not detected | Gas present and at correct pressure. Combustion C02 level. |
| Condition of flue. | ||
| Ignition electrodes. | ||
| Ignition harness and connections. Flame sense harness. | ||
| Flame sense cables and connections. Gas valve. | ||
| Otherwise replace control board. | ||
| FO | Internal error | Transformer. |
| All connections to control board. Otherwise replace control board. | ||
| F7 | Flame detected with no demand. | Gas valve |
| Flame sense electrodes/cables Moisture on control board. Blocked condensate trap. Otherwise replace control board. | ||
| FA | Flame detected after gas. Gas valve switched off. | Cables and connections to gas valve. Condensate trap. |
| Flue (for blockages). | ||
| Otherwise replace control board. | ||
| Fd | Reset button pressed by mistake | Press reset button again. |
Worcester GREENSTAR HIGHFLOW 440CDI ERP boiler error codes
| Error code | Description |
|---|---|
| A7 | Hot water NTC sensor defective. |
| A8 | Break in communication to weather compensating clip-in control or Greenstar Comfort IIRF |
| bl | Code plug not detected. |
| C6 | Fan speed too low. |
| E2 | CH flow NTC sensor defective. |
| E9 | Safety temp, limiter in CH flow has tripped. |
| EA | Flame not detected. Check, if it safe to do so: • if gas is on in the house • for frozen condensate pipe • for blocked flue outlet |
| FO | Internal error. |
| F7 | Flame detected even though boiler switched off. |
| FA | Flame detected after gas shut off. |
| Fd | Reset button pressed by mistake. |
Worcester basic error codes
| Locking Fault Code | Possible Cause |
|---|---|
| 9A | Boiler has been fitted with incorrect Heat Control Module (HTM). |
| 9U | The code plug could be faulty or not properly connected. |
| B7 | You need to replace the control board. |
| C6 | The system is running too fast or too slow. |
| C7 | Fan is not running or the airflow could be blocked. |
| D1 | Sensor could be wet, damaged or disconnected. The boiler will block for 300 seconds. |
| D1 | Boiler is overheating. |
| E2 | The Flow sensor has shorted, is damaged or disconnected. |
| E5 | The primary flow sensor has overheated. |
| E9 (error solution E9) | The main heat exchanger has overheated as the main temperature is 150 degrees. |
| E9 (error solution E9) | Maximum temperature sensor on the main heat exchanger cannot be recognised or has failed. |
| E9 (error solution E9) | The flue gas thermostat has overheated. |
| EA | Failure after four ignition attempts. The boiler will wait 30 seconds before another attempt is made. |
| EA | A flame has been extinguished due to either moisture in the sump, a blocked sump or strong wind in the flue. |
| EA | Gas valve coil has been disconnected. |
| EA | Flame has not extinguished within first 4 seconds of ignition. |
| EA | There is an error as the pump is not detecting water. Check the pressure gauge and re-pressurise to 1 bar. |
| Blocking Fault Code | Possible Cause |
|---|---|
| A1 | Little or no water in the system- Check pressure gauge and re-pressurise to 1 bar. |
| C1 | Fan has stopped. |
| EA | No flame is detected and so the boiler will block during 4 attempts before going to Locking fault. |
| EF | The boiler is operating at minimum burner load and there is higher flow temperature of 18 degrees. |
| 260 | Sensor has been disconnected or there is no water content- check pressure gauge and repressurise to 1 bar. |