Viessmann Vitodens 100-W B1HA PCB (control board)
The Viessmann Vitodens 100-W B1HA PCB manages the ignition, burner modulation, pump, and safety features of the boiler. If it malfunctions, the boiler may fail to start, become locked, or operate erratically. Users may observe fault codes such as F0, FC, Fd, FF, and E3. This PCB is compatible with the Vitodens 100-W B1HA and Vitodens 100-W B1KA models, among other options in the range. A technician must confirm through diagnosis whether it needs to be replaced when these fault symptoms are detected.
- Type of part
- PCBs (control boards)
- Status
- Refurbished
- Catalogue reference
- 7842194
- Warranty
- 1 year
Viessmann boilers compatible with reference 7842194
PCB with reference 7842194. Two confirmed compatibilities: Vitodens 100-W B1HA and Vitodens 100-W B1KA.
Proven compatibility
| Boiler model | Family | Verification |
|---|---|---|
| Viessmann Vitodens 100-W B1HA | Vitodens 100-W | Contrasted |
| Viessmann Vitodens 100-W B1KA | Vitodens 100-W | Contrasted |
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. 7842194 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 7842194. 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 7842194
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 is completely off, with no display or indicator lights on.
Cause: The PCB does not receive or manage the input power.
Check the main fuse and measure the input current to the boiler before replacing the PCB.
- 02
A fault code appears on the screen that does not disappear even after resetting the boiler.
Cause: The PCB is maintaining the lock because it continues to detect a fault in the safety component it monitors.
Note the exact code and first check the component it indicates (sensor, pressure switch, flame) before replacing the PCB.
- 03
It won't start even though there is a demand for heating or domestic hot water.
Cause: Fault in the ignition sequence managed by the PCB.
Check that gas is reaching the boiler, that there is correct water pressure, and that the gas valve is open before suspecting the electronics.
- 04
It stops on its own after running for a while.
Cause: Intermittent thermal fault in the PCB: a component fails when heated.
Note if the shutdown always occurs after a similar amount of operating time; this pattern suggests the PCB more than another cause.
Viessmann fault codes that require diagnosis
| Code | Fault | Technical checks |
|---|---|---|
| F0 | Burner blocked – internal fault. | The PCB/control unit (VBC113) has an internal fault and locks the burner. Check power supply, fuse F4 T2.5A, and connectors; if it persists after the reset, replace/code the board. |
| FC | Burner blocked – fan electrical control (control unit) faulty. | The fan control stage integrated into the PCB fails and the board does not control/read the fan, causing a lockout. Check the wiring and fan signal; if there is no external defect, replace the PCB. |
| Fd | Burner blocked – burner control unit fault. | Fault in the BCU/PCB that manages ignition and flame supervision; the boiler goes into lockout. Check electrodes/cables and possible EMC interferences; if it returns after reset, replace the PCB. |
| FF | Burner blocked – burner control unit fault. | BCU/PCB defect causing repeated burner lockout. After checking electrodes/cables and interferences, if the fault persists after the reset, replace the PCB. |
| E3 | Burner in fault state – fault in the safety chain. | If after checking the thermal limit/wiring the safety chain is correct, detection by the PCB may be the cause; replace the control board if necessary after testing. Confirm safety continuity and rule out false contacts. |
| b7 | Emergency mode – burner control unit fault. | BCU/PCB fault forcing emergency mode. Attempt reset; if it reappears, check power supply and connections; rule out external causes and, if confirmed, replace the PCB. |
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 7842194 PCB.
- Catalogue reference
- 7842194
- Uniclima internal SKU
- TECVV100
- Brand
- Viessmann
- Type of part
- PCBs (control boards)
- Units in stock
- 6 units
- Status
- Refurbished
- Warranty
- 1 year
- Shipping
- Delivery time shown at checkout
- Return
- 14 days
Manuals and technical documentation
Official documentation of the boiler, useful for locating the part and cross-referencing the fault codes.
- Viessmann Vitodens 100-W B1HA Manual (PDF) Document © Viessmann, provided as a technical reference.
Frequently asked questions about the PCB 7842194
Is the PCB for the Vitodens 100-W B1HA also suitable for the B1KA?
Spare parts related to Viessmann Vitodens 100-W
