Viessmann Vitodens 300 W WB3A Control PCB Ref. 7825241
The Viessmann Vitodens 300 W WB3A Control PCB is a component that manages the ignition, burner modulation, pump, and safety features of the boiler. When it malfunctions, the boiler may fail to start, lock out, or operate erratically. It can be found in models such as Vitodens 200-W WB2A and various models of Vitodens 300-W WB3A, among other boilers. Its replacement is necessary when errors such as F0, E4, b5, or b4 appear, indicating issues with the boiler's operation.
- Type of part
- PCBs (control boards)
- Status
- Refurbished
- Catalogue reference
- 7825241
- Warranty
- 1 year
Viessmann boilers compatible with reference 7825241
PCB with reference 7825241. Six confirmed compatibilities: Vitodens 200-W WB2A 26 kW and Vitodens 300-W WB3A 26 kW.
Verified compatibility
| Boiler model | Family | Verification |
|---|---|---|
| Viessmann Vitodens 200-W WB2A 26 kW | Vitodens 200-W (WB2A) | Verified |
| Viessmann Vitodens 300-W WB3A 26 kW | Vitodens 300-W (WB3A) | Verified |
| Viessmann Vitodens 300-W WB3A 35 kW | Vitodens 300-W (WB3A) | Verified |
| Viessmann Vitodens 300-W WB3A 49 kW | Vitodens 300-W (WB3A) | Verified |
| Viessmann Vitodens 300-W WB3A 66 kW | Vitodens 300-W (WB3A) | Verified |
| Viessmann Vitodens 300-W WB3B 35 kW | Vitodens 300-W (WB3B) | Verified |
Can't see your model or have questions? The printed reference takes precedence. How to check it · Send us a photo via WhatsApp.
How to check if ref. 7825241 is the part for your boiler
The part reference, model, and equipment revision must be verified against the manufacturer's documentation.
- Find the reference printed on the installed part and check whether it matches the catalogue reference 7825241. If it is not visible, do not identify the part from its shape alone.
- Check the full boiler model on its data plate and look for it in the model associations on this page.
- Compare the connections and physical body with the original part before installation.
- If anything is unclear, send us a photo of the marking via WhatsApp before placing your order.
Symptoms that require diagnosis on the PCB 7825241
The PCB controls the ignition, modulation, and safety features of the boiler. These are the typical symptoms and what to do:
Common symptoms and faults
- 01
The boiler does not ignite or respond to the controls.
Cause: The PCB has a problem that prevents the boiler from starting the ignition.
Check that the PCB is receiving power and that the fuses are not blown before replacing it.
- 02
The boiler is locking out and the display shows a fault code.
Cause: The PCB misinterprets the safety signals and locks the boiler, although the real problem may lie in another component.
Note the exact fault code: many Viessmann codes indicate problems with sensors or pressure before the PCB.
- 03
Communication with the thermostat or the control panel is lost.
Cause: The PCB stops communicating with the thermostat or the control panel.
Disconnect and reconnect the communication bus and reset the boiler before considering that the PCB is faulty.
- 04
The pump or some output does not activate even though the PCB gives the command.
Cause: The relays on the PCB can get stuck or not make good contact over time.
Listen for a click from the relay when the demand is activated; if it doesn't click, the problem is likely there.
Viessmann fault codes that require diagnosis
| Code | Fault | Technical checks |
|---|---|---|
| F0 | The burner is not working due to an internal fault. | This symptom may be related to the part, but it does not confirm that it is faulty. A technician must check the equipment and its inspection according to the manual before deciding on a repair or replacement. |
| E4 | The burner is not working due to a problem with the 24 V voltage. | There is a fault in the 24 V circuit of the control board. Measure the 24 VDC output and check the peripherals. If the voltage is correct and the fault persists, the PCB is defective and the technical diagnosis must confirm whether it is necessary to replace it. |
| b5 | Internal error in delivery control mode. | The control electronics have an internal fault. Make sure there are no programming errors or issues with the Vitotrol and reset. If the problem persists, replace the PCB. |
| b4 | The boiler measures as if it were 0 °C outside due to an internal fault. | The control board has a problem with the A/D converter or the measurement, resulting in an incorrect outdoor reading. Check the outdoor sensor and the resistances at the terminals. If everything is fine and the fault persists, the board is damaged and technical diagnosis must confirm if it needs to be replaced. |
These symptoms can have more than one cause. If your boiler displays a fault code, send it to us via WhatsApp along with a photo of the labeling, and we'll tell you if this is the part.
Data sheet for the Viessmann 7825241 PCB.
- Catalogue reference
- 7825241
- Uniclima internal SKU
- PLVI064
- Brand
- Viessmann
- Type of part
- PCBs (control boards)
- Units in stock
- 1 unit
- Status
- Refurbished
- Warranty
- 1 year
- Shipping
- Delivery time shown at checkout
- Return
- 14 days
Part data and available documentation
Contrast the label codes, PCB, and revision with the installed part; they are not necessarily equivalent references.
- Relay brand
- SCHRACK
- On the three white relays, 'SCHRACK' is read with moderate confidence: it is the brand of the relay mounted on the PCB, not necessarily the manufacturer of the complete board.
Frequently asked questions about the PCB 7825241
Is it compatible with a Vitodens 300 WB3B in addition to the WB3A?
Is it compatible with the Vitodens 333 WS3A?
What fault does this PCB solve in a Vitodens 200 WB2A?
Spare parts related to Viessmann Vitodens 300-W (WB3A)
