BoilerFaultCodesVaillant D.67 Fault Code
Also written as D67 — same fault.
The Vaillant D.67 fault code means: your boiler is simply taking a short, programmed break between heating cycles to protect its internal parts and operate more efficiently.. It appears on 37 Vaillant models in our database.
Technical description: Remaining burner anti-cycling time
What causes the Vaillant D.67 fault?
This occurs because the boiler has reached its target temperature and has temporarily shut down to prevent the system from turning on and off too frequently. It is a built-in safety feature designed to reduce wear and tear on the internal components and improve fuel efficiency. The boiler will automatically resume heating once a pre-set cooling period has passed.
This is more common during the 'shoulder' months of spring and autumn when the weather is mild and the boiler needs to produce less heat to keep your home warm.
DIY fix possible
Wait for 5 to 15 minutes for the countdown to finishEnsure your room thermostat is turned up high enough to call for heatCheck that your radiator valves are open to allow heat to dissipate
Find a Gas Safe engineer
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A cover plan would handle faults like D.67: no call-out fees, no surprise bills.
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Vaillant models that show the D.67 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 824E
- ecoMAX 828E
- Ecomax Condensing 600/800 series
- ecoMAX System 612
- ecoTEC
- ecoTEC 65kW
- ecoTEC Plus 615
- ecoTEC Plus 620
- ecoTEC Plus 625
- ecoTEC Plus 630
- ecoTEC Plus 635
- ecoTEC Plus 840
- ecoTEC plus aquaPLUS
- ecoTEC Pro / ecoTEC Plus
- ecoTEC sustain
- Home Combi
- Home System
- 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.67 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 835 manual (PDF)
- Vaillant ecoMAX manual (PDF)
- Vaillant ecoMAX System 612 manual (PDF)
Reviewed by the BoilerFaultCodes Editorial Team · Last reviewed 7 July 2026