Saunier Duval Isomax F35 H MOD 2 PCB Ref. 0020023308
When you open the hot water tap or turn on the heating, the Saunier Duval Isomax F35 H MOD 2 PCB (control board) Ref. 0020023308 activates to manage the ignition and modulation of the burner, as well as the operation of the pump and the safety features of the boiler. If this part fails, you will notice that the boiler does not start, locks out, or exhibits erratic behavior, which may be reflected in fault codes 13 or 20. This board is compatible with models such as Isomax F 35 H-MOD and Isotwin C 25 E, among others. A technician must confirm through diagnosis whether it needs to be replaced when faults or malfunctions occur.
Saunier Duval boilers compatible with reference 0020048284
PCB with reference 0020048284. Three confirmed compatibilities: Isomax F 35 H-MOD and Isotwin C 25 E.
Proven compatibility
| Boiler model | Family | Verification |
|---|---|---|
| Saunier Duval Isomax F 35 H-MOD | Isomax | Contrasted |
| Saunier Duval Isotwin C 25 E | Isotwin | Contrasted |
| Saunier Duval Isotwin C 30 E | Isotwin | 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 the reference 0020048284 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 0020048284. 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 0020048284
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 shuts down in lockout shortly after starting and needs to be reset manually each time.
Cause: The PCB may be interrupting the ignition cycle due to an incorrect reading from a safety element.
Check the pressure switch, the flue sensor, and the safety wiring before assuming it's the PCB.
- 02
There is no visible fault code, but the boiler simply does not respond to anything.
Cause: The microprocessor or the internal power supply of the PCB may have failed without displaying a warning.
Disconnect the boiler from the power supply for a couple of minutes and try again before replacing the PCB.
- 03
The domestic hot water is not heating even though the heating is working normally.
Cause: The PCB may not be activating the three-way valve or the domestic hot water circuit correctly.
Manually check that the three-way valve changes position before replacing the PCB.
- 04
The display shows incorrect symbols or segments that do not correspond to any known fault code.
Cause: A fault in the display circuit integrated on the PCB can show corrupted information.
Perform a complete network disconnection for one minute before concluding that the PCB is damaged.
Fault codes Saunier Duval that require diagnosis
| Code | Fault | Technical checks |
|---|---|---|
| 13 | Main PCB fault. | Fault in the main PCB or its connections causes loss of control/readings. Check power supply and wiring harness, connections with the panel/interface; if it persists, test or replace the PCB. |
| 20 | Communication/compatibility fault between user interface and main circuit (software/coding). | After replacement or misalignment, the PCB and the display do not share the product code or protocol; the PCB locks the equipment. Verify product and bus coding (MMI/eBUS), check wiring, and if not corrected by reprogramming, replace the PCB or interface. |
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 PCB 0020048284
- Catalogue reference
- 0020048284
- Uniclima internal SKU
- PLSA111
- Brand
- Saunier Duval
- 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
Part data and available documentation
Contrast the label codes, PCB, and revision with the installed part; they are not necessarily equivalent references.
- PCB reference (corrected)
- 0020023308
- Batch code
- 7415 0153 A
- Manufacturing date (code)
- 0188.04.24
- Voltage regulator on PCB
- STMicroelectronics L7805C2T
Manuals and technical documentation
Official documentation of the boiler, useful for locating the part and cross-referencing the fault codes.
- Saunier Duval Isomax F 35 H-MOD Manual (PDF)Document © Saunier Duval, provided as a technical reference.
Frequently asked questions about the PCB 0020048284
Does this PCB work for the Saunier Duval Isotwin C 30?
Is this PCB 0020023308 compatible with the Isomax C 30?
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