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boiler service, boiler repair, emergency repair
Worcester Greenstar Highflow 440 inst Boiler Fault Codes
| Display Code | 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 |
Talk 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 | 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 CO2 level Condition of flue Ignition electrodes Ignition harness and connections Flame sense harness Flame sense cables and connections Gas valve Otherwise replace control board |
| F0 | 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 pump 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 |
|
P1,P2,P3, P1... |
Please wait, initialisation in progress No central heating, hot water OK No functions Poor performance / noises Noisy ignition |
Replace fuse S12. Otherwise replace control board. Demand signal from roomstat/CH timer. (or link fitted at ST4). CH channel of facia mounted programmer (if fitted). CH control knob position. Flow turbine. Demand signal from DHW timer (or link fitted at ST8). DHW channel of facia mounted programmer (if fitted). Fan/fan harness. Sensors not fixed or out of specification. Gas pressure/blockage. Water pressure/blockage. CO2 mix. Flue blockage. Spark electrodes/cables. Gas valve. Gas supply. CO2 mix. Seals. |