Saunier Duval Thelia AS 23 Ignition Transformer Ref. 05210600
Saunier Duval Thelia incorporates the ignition transformer Thelia AS 23, which is responsible for generating the spark needed to ignite the burner. When this part fails, the boiler attempts to start without being able to form a flame, which can result in fault codes F.28 and F.29, indicating ignition issues and failed re-ignition. This transformer is compatible with models such as Thelia 23, Thelia 623, and Thelia 23 E, among other boilers in the Thelia range. It is recommended to replace it when the mentioned symptoms occur or in case of a lockout due to ignition failure.
VAT included
Consult via WhatsAppSaunier Duval boilers compatible with reference 05210600
Ignition transformer with reference 05210600. Four confirmed compatibilities: Thelia 23 and Thelia 623.
Proven compatibility
| Boiler model | Family | Verification |
|---|---|---|
| Saunier Duval Thelia 23 | Thelia | Contrasted |
| Saunier Duval Thelia 623 | Thelia | Contrasted |
| Saunier Duval Thelia 23 E | Thelia | Contrasted |
| Saunier Duval Themis 23 E | Themis | 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. 05210600 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 05210600. 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 ignition transformer 05210600 resolves.
The ignition transformer generates the high voltage for the spark of the electrodes. These are the typical symptoms and what to do:
Common symptoms and faults
- 01
The boiler does not ignite and there is no visible spark at the electrode.
Cause: The transformer is broken and does not produce the necessary high voltage.
With the boiler in ignition cycle, check if there is a visible spark at the electrode before replacing the transformer.
- 02
The spark is weak or intermittent, and the ignition takes longer than usual.
Cause: The transformer insulation is damaged or the connection to the electrode is loose.
Check that the high voltage cable is properly connected to the transformer and the electrode, without any slack.
- 03
The ignition fault only appears when the boiler has been running for a while and disappears if it is allowed to cool down.
Cause: The transformer heats up near the burner and loses performance intermittently.
Note if the fault occurs only when the boiler is hot; if it disappears after cooling for a few minutes, do not rule out a specific thermal issue.
- 04
The boiler locks with a ignition fault warning on the display after several attempts.
Cause: The control board does not detect a flame because there is not enough spark and it locks the unit for safety.
Check the fault code: if it is for ignition and not for flame, the transformer or its wiring are the first points to check.
Fault codes from Saunier Duval that this spare part resolves.
| Code | Fault | Diagnosis and solution |
|---|---|---|
| F.28 | Ignition fault: the boiler fails to ignite the burner during startup (no flame formation after several attempts). | The ignition transformer is part of the ignition system/group (transformer, cable, connector, and electrode); if it does not generate the spark, the boiler will not ignite and shows F.28. Check: measure the output of the transformer/spark at the electrode with the boiler on demand; check the continuity of the high voltage cable and connections, and rule out gas issues (pressure, valve) and grounding problems first. |
| F.29 | Failed re-ignition attempts during operation: the flame is lost and the boiler fails to re-ignite. | Sources document 'ignition failures in the ignition transformer' as the cause of F.29; if the transformer does not produce a stable spark when reigniting after a flame loss, F.29 is triggered. Check: spark at the electrode during reignition and condition of the transformer/cable; also rule out temporary gas shortage and flue recirculation/blockage. |
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.
Saunier Duval Ignition Transformer Datasheet 05210600
- Catalogue reference
- 05210600
- Brand
- Saunier Duval
- Type of part
- Transformers
- Units in stock
- 7 units
- Status
- Refurbished
- Warranty
- 1 year
- Shipping
- Delivery time shown at checkout
- 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.
- Model
- ZIG 2
- Voltage
- 220-240V~
- Network frequency
- 50-60Hz
- Spark frequency
- 10 Hz
- Maximum temperature
- 125°C
- Standard
- DIN DVGW 88.01f142
Frequently asked questions about the ignition transformer 05210600
Is this ignition transformer compatible with the Saunier Duval Thelia 23?
Which boiler models are compatible with the transformer TETAS23?
What fault codes indicate that the transformer needs to be replaced?
What frequency does the ignition transformer of the Saunier Duval Thelia 623 produce sparks?
What is the maximum temperature that the ZIG 2 transformer used in the Saunier Duval Themis 23 E can withstand?
Is the ZIG 2 transformer from Saunier Duval Thelia AS 23 approved?
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