Ariston DIA 80 Fault codes & diagnostics

3 fault codes with plain-English explanations, severity ratings, DIY guidance, and repair cost estimates.

System Natural Gas 23.3 kW Discontinued

The fault code is already on your display

Note it down before pressing reset — resetting clears the code immediately. How to read fault codes →

Just want the most common Ariston DIA 80 faults?
The top 6 problems in plain English — with causes, DIY checks and repair costs.
Fault codes

All 3 documented codes

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7.

Your boiler is working correctly but is currently being told not to provide heating by your thermostat, timer, or because it is set to summer mode.

Low DIY-safe

What to check first

  1. Check that your room thermostat is turned up higher than the current room temperature.
  2. Ensure the boiler is not set to 'Summer' mode if you are trying to use the central heating.
  3. Verify that your external programmer or timer is set to an 'On' period.
Full explanation for 7.
8.

Your boiler is failing to detect that you need heating or hot water, often because one of its internal sensors or control knobs is faulty.

High Engineer only £90-180

Parts commonly replaced

  • NTC Temperature Sensor
  • Potentiometer
  • Control PCB
Full explanation for 8.
YELLOW FLUE CONTROL LED

Your boiler has sensed that exhaust fumes are not leaving the chimney correctly, causing it to shut down for your safety.

Emergency Engineer only £120-280

Parts commonly replaced

  • Flue Gas Sensor
  • Fan Assembly
  • Air Pressure Switch
Full explanation for YELLOW FLUE CONTROL LED