Saunier Duval Isofast F 35 E1 PCB Ref. 840329
The Saunier Duval Isofast F 35 E1 PCB (control board) Ref. 840329 is a crucial component for the control of the boiler, managing functions such as ignition, burner modulation, and system safety features. When it fails, the boiler may not start, become locked, or exhibit erratic behavior, which can result in fault codes 13 or 20. This board is compatible with models from the Isofast and Isomax ranges, such as the C 28 E1, F 35 E1, and others. It is recommended to replace it upon detecting these symptoms or faults in operation.
VAT included
Consult via WhatsAppSaunier Duval boilers compatible with reference S1019000
PCB with reference S1019000. 11 verified compatibilities: C 28 E1 and C 28 E1 NOX.
Proven compatibility
| Boiler model | Family | Verification |
|---|---|---|
| Saunier Duval C 28 E1 | Isofast | Contrasted |
| Saunier Duval C 28 E1 NOx | Isofast | Contrasted |
| Saunier Duval C 35 E1 | Isofast | Contrasted |
| Saunier Duval F 28 E1 | Isofast | Contrasted |
| Saunier Duval F 35 E1 | Isofast | Contrasted |
| Saunier Duval C 28 E2 | Isomax | Contrasted |
| Saunier Duval C 28 E204 | Isomax | Contrasted |
| Saunier Duval C 28 E205 | Isomax | Contrasted |
| Saunier Duval F 28 E2 | Isomax | Contrasted |
| Saunier Duval F 28 E204 | Isomax | Contrasted |
| Saunier Duval F 28 E205 | Isomax | 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. S1019000 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 S1019000. 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 S1019000 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 fault appears and disappears on its own; sometimes just touching the boiler or an external vibration is enough to cause it to fail.
Cause: The solder joints on old PCBs crack over time, and a contact that opens due to minimal vibration causes intermittent faults.
With the boiler turned on and accessible, gently tap the area of the PCB to see if the fault reoccurs before replacing it.
- 02
The boiler works well when first turned on but fails after running for a while and when it is already hot.
Cause: Heat expands the tracks and solder joints on the PCB, and a cold solder joint that makes contact when cold can open up as it expands.
Note how long it takes to fail from ignition; this information helps to differentiate a thermal fault of the PCB from another cause.
- 03
If the cover is opened, greenish or whitish stains can be seen on wires or solder joints.
Cause: Manual wiring and the years promote oxidation at the connection points, especially in a humid room.
If you have access, visually check those points before declaring the PCB lost; sometimes a cleaning resolves the contact issue.
- 04
The boiler has been experiencing sporadic faults for some time that have never been fully diagnosed.
Cause: This old PCB does not always provide clear fault codes, so an intermittent manual wiring fault can go unnoticed for a long time.
Before replacing it, check if the fault matches any pattern (time of day, temperature, use of domestic hot water) that helps narrow down the cause.
Fault codes from Saunier Duval that this spare part resolves.
| Code | Fault | Diagnosis and solution |
|---|---|---|
| 13 | Main printed circuit board fault. | The main PCB (S1019000) does not pass the internal self-diagnosis; this is usually due to an electronics/EEPROM fault or the PCB not generating its internal voltages. Check the 230 V input, fuse, and low voltages (5/15/24 V) on the PCB; if these are correct and the wiring is OK, replace the PCB. |
| 20 | Communication fault between the user interface and the main PCB. | Communication channel/ebus fault on the main board, incompatibility between interface and PCB or defective connection/harness. Check the interface power supply from the board, connectors/harness and test with a known interface; if it persists, the cause is 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 Saunier Duval S1019000 PCB.
- Catalogue reference
- S1019000
- Brand
- Saunier Duval
- Type of part
- PCBs (control boards)
- Units in stock
- 1 unit
- 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.
- Transformer - primary voltage
- 220 V
- Transformer - secondary voltage
- 24 V
- Transformer - frequency
- 50 Hz
- Transformer - power
- 8 VA
- Transformer - fuse
- 125 mA T
- Transformer - number
- N° 78845
- The reference published in the catalog (S1019000) was incorrect. The correct one is 840329.
Frequently asked questions about the PCB S1019000
Why is the reference for this PCB 840329 and not S1019000 as it appeared before?
Which brand manufactures this old PCB from the Isofast range?
Does this PCB fit a Saunier Duval Isofast F 28 E1?
Does this PCB also work for the Saunier Duval Isomax C 28 E2?
Spare parts related to Saunier Duval Isomax
