Anstoss Ignition Transformer (ZIG 2) For Saunier Duval Thelia 623 - Ref. 05210600
Ignition transformer manufactured by Anstoss Regelgeräte GmbH (brand ZIG, model ZIG 2) for Saunier Duval boilers in the Thelia, Thema, Themis, and Combitek ranges. It generates the high-voltage spark that ignites the gas burner. It operates at 220/240V~ 50-60Hz and withstands up to 125°C. It is replaced when the boiler does not ignite, the fan is heard but the spark does not occur, or it locks 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
A buzzing sound is heard in the transformer, but no spark is coming from the electrode.
Cause: The transformer can receive current and make noise, but it does not produce the necessary high voltage due to a damaged winding.
Check that the high voltage cable and the electrode cap are not cracked or leaking before declaring the transformer faulty.
- 02
The spark jumps but is weak, orange in color, or cuts off before igniting the burner.
Cause: A transformer that loses output voltage generates an insufficient arc to reliably ignite the gas.
Check the distance and condition of the ignition electrode (normally 3-4 mm and free of rust) before replacing the transformer.
- 03
The boiler tries to ignite several times in a row and ends up locking out due to a flame failure.
Cause: If the transformer does not deliver high voltage consistently, the control unit exhausts the programmed ignition attempts and locks out for safety.
Check that the electrode and its ceramic are not broken or dirty with soot, as this can also prevent the arc even if the transformer is functioning properly.
- 04
The ignition fault mainly occurs when the boiler has been off for a while, when it's cold.
Cause: A transformer with degraded internal insulation may fail more when cold, before warming up with its own consumption.
Note if the fault is more frequent during cold starts to guide the diagnosis before replacing the part.
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
- 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.
- Model (marking)
- ZIG 2
- Voltage
- 220/240 V~
- Network frequency
- 50-60 Hz
- Maximum temperature
- 125 °C
- Manufacturer
- Anstoss Regelgeräte GmbH, Endresstraße 21, A-1230 Vienna (Liesing), Austria — founded by Helmut Anstoss in 1969, specialized in gas ignition devices
Frequently asked questions about the ignition transformer 05210600
Is the ZIG 2 ignition transformer for the Saunier Duval Thelia 623 an original product from Saunier Duval?
What voltage does the ZIG 2 transformer of the Thelia 623 accept?
What is the maximum temperature that this ZIG 2 transformer can withstand?
How many boiler models are compatible with the ZIG 2 transformer?
What fault codes are documented for this transformer?
What is the reference for the ignition transformer ZIG 2 for the Saunier Duval Thelia 623?
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