Transformer for Vaillant Thermocompact VC 242 E Boiler
In Vaillant Thermocompact boilers, the transformer for Vaillant Thermocompact VC 242 E is responsible for generating the spark needed to ignite the burner. When this part fails, the boiler attempts to start without achieving the flame, which can trigger the fault code F.29: ignition failure. This transformer is compatible with several models from the Thermocompact and Combicompact ranges, such as the VC 180 XE, VC 182 E, and VCW 242 E, among others. It should be replaced when the ignition attempts are unsuccessful and the boiler locks out.
VAT included
Consult via WhatsAppVaillant boilers compatible with reference 091235
Ignition transformer with reference 091235. Ten verified compatibilities: VC 180 XE and VC 182 E.
Proven compatibility
| Boiler model | Family | Verification |
|---|---|---|
| Vaillant VC 180 XE | Thermocompact / Combicompact VC (heating only) | Contrasted |
| Vaillant VC 182 E | Thermocompact / Combicompact VC (heating only) | Contrasted |
| Vaillant VC 240 XE | Thermocompact / Combicompact VC (heating only) | Contrasted |
| Vaillant VC 280 XE | Thermocompact / Combicompact VC (heating only) | Contrasted |
| Vaillant VCW 180 XE | Thermocompact / Combicompact VCW (combi) | Contrasted |
| Vaillant VCW 182 E | Thermocompact / Combicompact VCW (combi) | Contrasted |
| Vaillant VCW 240 XE | Thermocompact / Combicompact VCW (combi) | Contrasted |
| Vaillant VCW 242 E | Thermocompact / Combicompact VCW (combi) | Contrasted |
| Vaillant VCW 280 XE | Thermocompact / Combicompact VCW (combi) | Contrasted |
| Vaillant VCW Vent 240 E | Thermocompact / Combicompact VCW (combi) | 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. 091235 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 091235. 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 091235 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 turn on, there are no lights or display.
Cause: The transformer powers the low voltage part of the PCB; if it fails, the electronics do not receive power.
Measure with a multimeter that 230V is reaching the primary before assuming that the transformer is damaged.
- 02
The boiler starts and stops by itself for no apparent reason.
Cause: An unstable output in the secondary causes the PCB to lose voltage intermittently and reset.
Check that the connections to the transformer are secure and free of rust; often the issue lies with the connector, not the transformer.
- 03
The differential or the internal fuse of the boiler trips when it is plugged in.
Cause: A transformer with the winding short-circuited consumes more current than normal and trips the protection.
Disconnect the transformer from the circuit and check if the fuse keeps blowing; that way you will know if the problem is before replacing it.
- 04
A louder than usual buzzing is heard in the area of the PCB.
Cause: A loose core of laminations or damaged windings generates vibration and audible noise.
Listen to see if the buzzing stops when you disconnect the boiler; if it continues to sound with the boiler off, investigate other causes.
Fault codes from Vaillant that this part resolves.
| Code | Fault | Diagnosis and solution |
|---|---|---|
| F.29 | Ignition fault / the flame goes out during operation and re-ignition attempts are unsuccessful. | The ignition transformer is the component that generates the high voltage for the spark; if it is faulty, a stable spark is not produced and the boiler fails to ignite, triggering F.29. Check: ensure that the spark reaches the electrode (no spark with correct gas and grounding points to the transformer/ignition cable); measure the continuity of the transformer and replace if it does not generate the spark. |
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 091235 ignition transformer datasheet
- Catalogue reference
- 091235
- Brand
- Vaillant
- 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.
- primary
- PRI ~230V 50/60Hz
- secondary
- SEC 17V
- power
- 18.4VA
- fuse
- 1,25AT
- Insulation class
- EI60
- certification
- CE, oval-shaped mark type UL/cULus
Manuals and technical documentation
Official documentation of the boiler, useful for locating the part and cross-referencing the fault codes.
- Vaillant VC 182 E Manual (PDF)Document © Vaillant, provided as a technical reference.
Frequently asked questions about the ignition transformer 091235
Is this transformer suitable for the Vaillant VC 242 E?
What secondary voltage does the transformer Ref. 091235 provide?
What fuse does the transformer of the VC 242 E use?
Is this transformer compatible with the VCW 240 XE?
Spare parts related to Vaillant Thermocompact / Combicompact VCW (combi)
