
Vaillant Ignition Transformer VMW ES 28 362 5 R3 Comelit T601817/E Ref. 287450
The Ignition Transformer Vaillant VMW ES 28 362 5 R3 Comelit T601817/E Ref. 287450 is the component responsible for generating the spark needed to ignite the burner of the boiler. If this part fails, the boiler will attempt to start unsuccessfully, which may result in fault codes F.28 and F.29. This transformer is compatible with several boiler models, including Vaillant Turbo Tec, Atmo Tec, and VC, among others. It is recommended to replace the transformer when the boiler has difficulties igniting or maintaining the flame.
VAT included
Consult via WhatsAppVaillant boilers compatible with reference 287450
Ignition transformer with reference 287450. 12 verified compatibilities: VMW ES 242/3 and VMW 242-3.
Proven compatibility
| Boiler model | Family | Verification |
|---|---|---|
| Vaillant VMW ES 242/3 | Vaillant Turbo Tec / Turbo Pro (VMW) | Contrasted |
| Vaillant VMW 242-3 | Vaillant Turbo Tec / Turbo Pro (VMW) | Contrasted |
| Vaillant VMW 242-5 | Vaillant Turbo Tec / Turbo Pro (VMW) | Contrasted |
| Vaillant VMW 240-5 | Vaillant Turbo Tec / Turbo Pro (VMW) | Contrasted |
| Vaillant VMW 282-5 | Vaillant Turbo Tec / Turbo Pro (VMW) | Contrasted |
| Vaillant VM 242-5 | Vaillant Atmo Tec / VM (heating only) | Contrasted |
| Vaillant VM 282-5 | Vaillant Atmo Tec / VM (heating only) | Contrasted |
| Vaillant VC 242 E | Vaillant VC / VCM (combi-compact) | Contrasted |
| Vaillant VCM 242 E | Vaillant VC / VCM (combi-compact) | Contrasted |
| Vaillant VCM 282 E | Vaillant VC / VCM (combi-compact) | Contrasted |
| Vaillant VMI 280-7 | Vaillant VMI | Contrasted |
| Vaillant VMI 282-7 | Vaillant VMI | 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. 287450 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 287450. 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 287450 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 tries to ignite several times, you can hear the gas flowing but the flame does not ignite.
Cause: The ignition transformer does not generate enough spark to ignite the gas in the burner.
Check the ignition electrode and its cable: if they are dirty, wet, or improperly positioned, the problem may not be with the transformer.
- 02
The boiler keeps locking out due to ignition failure and you have to reset it often.
Cause: A weak ignition transformer produces an insufficient spark that the control board does not detect as a valid flame.
Check the distance and condition of the electrode before replacing the transformer: an incorrect gap can cause the same symptom.
- 03
A clicking or buzzing sound is heard when trying to ignite, followed by a lockout.
Cause: An internal arc due to deteriorated insulation in the transformer alters the normal ignition sound and reduces the effective spark.
With the boiler cold, check for signs of burning or corrosion on the transformer connections before considering it faulty.
Fault codes from Vaillant that this part resolves.
| Code | Fault | Diagnosis and solution |
|---|---|---|
| F.28 | Fault during start-up: the boiler fails to ignite the burner in the start-up phase. | The ignition transformer is part of the ignition system (transformer + cable + electrode); if the transformer fails, it does not generate the high voltage for the spark, and the boiler aborts the start-up without detecting a flame. Verify: measure the transformer's output voltage to the electrode and check for a spark at each start-up; if there is no spark and the wiring/electrode are fine, the transformer is the cause. |
| F.29 | The flame goes out during operation and re-ignition attempts fail. | The Vaillant service documentation explicitly lists "the ignition transformer has a spark fault" as the cause of F.29: if the transformer does not reignite after a flame failure, the lockout is triggered. Verify: check the spark generation of the transformer during ignition retries and rule out poor grounding, gas pressure, and condensate pipe before. |
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.
Vaillant 287450 ignition transformer datasheet
- Catalogue reference
- 287450
- Brand
- Vaillant
- Type of part
- Transformers
- Units in stock
- 3 units
- Status
- Refurbished
- Warranty
- 1 year
- Shipping
- Delivery time shown at checkout
- Return
- 14 days
Manuals and technical documentation
Official documentation of the boiler, useful for locating the part and cross-referencing the fault codes.
- Vaillant VMW 242-5 Manual (PDF)Document © Vaillant, provided as a technical reference.












