Saunier Duval PCB Thema/Isotwin/Isosplit/Thematek
The Saunier Duval Thema/Isotwin/Isosplit/Thematek PCB controls the ignition, burner modulation, pump, and safety features of the boiler. When it fails, the boiler may not start, become locked, or operate erratically. This component is compatible with several models, including Thema, Isotwin, and Isosplit. The confirmed manufacturer reference is S10470 and the firmware is labeled as SYMSI7.0. It is recommended to replace it when these symptoms occur, to restore the normal operation of your boiler.
VAT included
Consult via WhatsAppHow to check if it 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 —. If it is not visible, do not identify the part by 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 (control board) 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 shows no signs of life: no display or fan noise.
Cause: The PCB is responsible for receiving the electrical supply so that the other components can function.
Check the fuse on the PCB and make sure the boiler is receiving stable power from the grid before replacing it.
- 02
A fault code remains displayed on the screen that does not clear when resetting.
Cause: The PCB keeps the fault as a safety measure until it verifies that the real cause has been resolved.
Identify the code in the manual: if it indicates an external sensor, check that component before replacing the PCB.
- 03
The burner ignites normally, but the flame appears unstable, rising and falling without reason.
Cause: The PCB adjusts the flame according to the demand, and a fault in this function causes that fluctuation.
First, rule out the inlet gas pressure and the condition of the electrode, as they can produce a similar symptom.
- 04
The boiler works but loses communication with the thermostat or the control unit frequently.
Cause: The communication bus with the external regulator goes through the PCB, and an intermittent fault here cuts the signal.
Check the wiring and the bus terminals on the PCB before considering it faulty.
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.
PCB data sheet
- Type of part
- PCBs (control boards)
- Units in stock
- 5 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.
- firmware code/printed name
- SYMSI7.0
Manuals and technical documentation
Official documentation of the boiler, useful for locating the part and cross-referencing the fault codes.
- Saunier Duval Thema/Isotwin/Isosplit/Thematek Electronic Manual (PDF)Document ©, provided as a technical reference.
Frequently asked questions about the PCB (control board)
What code is printed on this PCB from Saunier Duval Thema/Isotwin/Isosplit/Thematek?
Is this PCB PLCC24FF compatible with any model of Saunier Duval?
Which manufacturer produces the PCB PLCC24FF?
What should I do if my boiler has faults and I need a PCB?
Where can I find more information about the PCB PLCC24FF?
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