Truma Combi error code E 121 H
Combustion Failure: Flame unstable. Flame unstable during operation - potential combustion issue (air, fuel, spark).
What to check, and in what order, is in the app. The flow Truma Combi — Ignition / Electrode Diagnostics (Code 0088) walks this code step by step with the pass/fail measurements, wiring schematics and procedures that go with it, and it works offline in the bay.
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- Truma Combi Service HandbookTruma
- Truma Combi Service Handbook (TrumaCorp, 20 pp; technician training handbook with Common Error Codes table and per-code Further Details sections) (rv-tech-resources/58-truma-combi-hydronic/Truma-Combi-Service-Handbook_TrumaCorp_20pp.pdf)
- Truma Combi Diagnostics Catalogue (canonical 57-code reference, external PDF at leisureshopdirect.com/pdf/370196265.pdf)
- Truma Combi 4 / 6 / Plus / E / D Technician Service Diagnostic Reference (rv-tech-resources/58-truma-combi-hydronic/Truma_Combi_4_6_Plus_E_D_Technician_Service_Diagnostic_Reference.md)
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