
PCB Baxi Roca RS 20/20 F Code 5S023/A
The control PCB Roca RS 20/20 F 5S023/A manages the ignition, burner modulation, pump, and safety features of the boiler. When it fails, the boiler may not start, lock out, or behave erratically, which can lead to faults such as 60-90, 50-70-90, or 40-60-70-90. This PCB is compatible with boilers from the RS 20/20 range, including the RS 20/20 F model. It should be replaced when these symptoms or operational faults occur.
VAT included
Consult via WhatsAppBaxi Roca boilers compatible with reference 122121410
PCB with reference 122121410. A proven compatibility: RS 20/20 F.
Proven compatibility
| Boiler model | Family | Verification |
|---|---|---|
| Baxi Roca RS 20/20 F | RS 20/20 | 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. 122121410 is the part for your boiler
What determines it is not the boiler model, but the reference printed on the part you already have installed.
- Find the reference printed on the installed part and check whether it matches the catalogue reference 122121410. 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 and faults that the PCB 122121410 resolves.
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 respond to any commands and the display is off.
Cause: The PCB does not distribute power to the other electronic components.
Check that power is reaching the boiler and that the main fuse is not blown before inspecting the PCB.
- 02
A different fault code appears each time it is restarted.
Cause: An internal fault in the PCB causes erratic readings from the connected sensors.
Note each code that appears; if they are always different and unrelated to each other, it is more likely to be the PCB and not a specific sensor.
- 03
The heating works but the domestic hot water does not.
Cause: The PCB does not switch correctly between the two operating modes.
First, check the condition of the three-way valve or the flow sensor, as they can also cause this symptom.
- 04
The lock pilot light is on and there is no way to reset it.
Cause: The reset circuit of the PCB does not respond when pressing the button.
Cut the main power for one minute and try the reset again before considering that the PCB is faulty.
Fault codes for Baxi Roca that this part resolves.
| Code | Fault | Diagnosis and solution |
|---|---|---|
| 60-90 | Flame relay is not working properly or is stuck/off. | The flame relay is integrated into the PCB 122121410; if it sticks or does not switch, the PCB does not validate the ionisation signal and locks out. Check if the PCB energises the relay and if it switches by measuring voltage/continuity during demand; if it does not operate with correct inputs, replace the PCB. |
| 50-70-90 | Fault in the safety relay, does not close after demand. | The safety relay is part of the PCB 122121410; if its contacts do not close, the safety chain is not enabled and the boiler goes into lockout. Check the relay excitation and contact continuity on the PCB during demand; if it does not switch with correct input signals, the PCB is faulty. |
| 40-60-70-90 | Safety relay, very long ignition timing. | The ignition timing and safety relay are governed by the PCB 122121410; a fault in the relay/timer on the PCB causes the time to exceed and lock out. Check the control board to relay command and spark/validation times; if the relay does not release in time with correct input conditions, 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 Baxi Roca PCB 122121410
- Catalogue reference
- 122121410
- Brand
- Baxi Roca
- Type of part
- PCBs (control boards)
- Units in stock
- 9 units
- Status
- Refurbished
- Warranty
- 1 year
- Shipping
- 1-2 business days
- Return
- 14 days
Data read on the part and in the manufacturer's documentation
What we have not been able to verify does not appear here.
- PCB code
- 5S023/A
- Additional code
- 9824
Manuals and technical documentation
Official documentation of the boiler, useful for locating the part and cross-referencing the fault codes.
- Baxi Roca RS 20/20 F manual (PDF)Document © Baxi Roca, provided as a technical reference.




