BoilerFaultCodesVaillant d.80 Fault Code
Also written as D80 — same fault.
The Vaillant d.80 fault code means: this code is simply an information display showing the total number of hours your boiler has been running since it was installed; it is not an error and requires no action.. It appears on 26 Vaillant models in our database.
Technical description: Number of heating system operating hours in h (Total) (ecoMAX 800)
DIY fix possible
This fault may be fixable without an engineer. Check your manual first.
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Vaillant models that show the d.80 fault code
Click a model for the full fault code list and model-specific repair notes.
- Atmomax
- ecoFIT Pure 418
- ecoFIT Pure 425
- ecoFIT Pure 435
- ecoFIT Pure 825
- ecoFIT Pure 830
- ecoFIT Pure 835
- ecoMAX
- ecoMAX 613
- ecoMAX 618
- ecoMAX 622
- ecoMAX 635
- Ecomax Condensing 600/800 series
- ecoMAX System 612
- ecoTEC 65kW
- ecoTEC plus aquaPLUS
- ecoTEC sustain
- Home Combi
- Thermocompact
- Turbomax 824/828
- Turbomax Plus
- Turbomax Plus 824/828E
- Turbomax Plus 828
- Turbomax Plus 828 E
- Turbomax Plus VUW 242E
- Turbomax Plus VUW 242EH
Source
Vaillant d.80 fault code information on this page is sourced and cross-checked against the official Vaillant service / installation manuals for each affected model.
- Vaillant ecoFIT Pure 425 manual (PDF)
- Vaillant ecoFIT Pure 835 manual (PDF)
- Vaillant Ecomax Condensing 600/800 series manual (PDF)
Reviewed by the BoilerFaultCodes Editorial Team · Last reviewed 31 August 2026