The Vaillant company is one of the leaders in production of boilers. The multilevel quality control, original spares, advanced technologies – here are the main features of Vaillant boilers. Unfortunately, its boilers can break down as well. The troubleshooting system provided below in form of a table will help to find the cause of any breakdown.
| Status code | Meaning |
|---|---|
| S.00 | Heating: No heat demand |
| S.02 | Heating mode: Pump pre-run |
| S.03 | Heating mode: Ignition |
| S.04 | Heating mode: Burner on |
| S.06 | Heating mode: Fan overrun |
| S.07 | Heating mode: Pump overrun |
| S.08 | Heating, remaining anti-cycling time xx mins |
| S.10 | Domestic hot water requirement via impeller sensor |
| S.14 | DHW mode: Burner on |
| S.20 | Hot water requirement |
| S.22 | DHW mode: Pump pre-run |
| S.24 | DHW mode: Burner on |
| S.31 | No heat demand: Summer mode |
| S.34 | Heating mode: Frost protection |
| S.46 | Comfort protection mode, flame loss at minimum load |
| Fault | Cause | Measure |
|---|---|---|
| Product does not start up: - No hot water - Heating remains cold | The gas isolator cock installed on-site and/or the gas isolator cock on the product is closed. | Open both gas isolator cocks. |
| The power supply in the building is disconnected. | Check the fuse in the building. The product switches on automatically when the power is restored. | |
| The product is switched off. | Switch on the product ("Switching on the product" section). | |
| The heating flow temperature is set too low or to the Heating off position, and/or the hot water temperature is set too low. | Set the heating flow temperature and hot water temperature ("Setting the heating flow temperature" section/-* "Setting the hot water temperature" section). | |
| The system pressure is insufficient. Low water pressure in the heating installation (fault message: F.22). | Fill the heating installation ("Filling the heating installation" section). | |
| There is air in the heating installation. | Have your competent person purge the heating installation. | |
| After three unsuccessful attempts to ignite the flame, the product switches to fault mode (fault message: F.28). | Press the fault clearance key for one second. The product makes another attempt to ignite the flame. If you have been unable to eliminate the ignition fault after three fault clearance attempts, consult a competent person. | |
| Hot water generation functioning correctly; heating does not start up. | The external controller is not set correctly. | Set the external controller correctly (-* Controller operating instructions). |
| Display | Meaning |
|---|---|
| S. 0 | No heat demand |
| S.1 | Fan running |
| S. 2 | Water pump running |
| S. 3 | Ignition sequence |
| S. 4 | Burner ignited |
| S. 5 | Fan and pump running |
| S. 6 | Fan over run |
| S. 7 | Pump over run |
| S. 8 | Anti cycling mode |
| S.10 | Hot water demand |
| S.11 | Fan running |
| S.13 | Ignition sequence |
| S.14 | Burner ignited |
| S.15 | Fan and pump running |
| S.16 | Fan over run |
| S.17 | Pump over run |
| S.20 | Warmstart demand |
| S.21 | Fan running |
| S.22 | Pump running |
| S.23 | Ignition sequence |
| S.24 | Burner ignited |
| S.25 | Fan and water pump running |
| S.26 | Fan over run |
| S.27 | Pump over run |
| S.28 | Anti cycling mode |
| S.30 | No heating demand from external controls (clamp 3-4 open) |
| S.31 | Central heating thermostat knob turned off or no heat demand by the eBUS control unit |
| S.32 | Heat exchanger antifreeze active, as fan speed variation is too high. Appliance is within the waiting time of the operation block function |
| S.34 | Antifrost mode active |
| S.36 | No heating demand from low voltage controls (clamp 7-8-9) |
| S.41 | Water pressure > 2,9 bar |
| S.42 | Response from accessory modul or defective condensate pump is blockinq burner operation |
| S.52 | Water pressure > 2,9 bar |
| S.53 | Appliance is within the waiting period of the operation block function due to water shortage (VL-RL spread too big) |
| S.54 | Appliance is within the waiting period of the operation block function due to water shortage (temperature gradient) |
| S.96 | Return-sensor check is running, demand (DHW or heatinq) is blocked |
| S.97 | Water pressure sensor check is running, demand (DHW or heatinq) is blocked |
| S.98 | Flow-/Return-sensor check is running, demand (DHW or heating) is blocked |