Alpha CD range Fault Codes
The Alpha CD range — CD24C, CD28C and CD35C combis chief among them — was Alpha's volume seller through the 2000s and into the 2010s, prized then as a budget workhorse. Surviving examples are now genuinely old boilers, and their fault reporting is of its era: E-prefixed codes on a simple display, covering ignition failure, overheat, sensor faults, fan/flue problems and pressure. Diagnosis on a CD is inseparable from its age. Every fault carries the same footnote — the repair-versus-replace arithmetic — and an honest engineer will run it with you: parts remain obtainable and individually cheap, but a 15-to-20-year-old budget boiler asking for its second major component in a year is answering the question itself. The codes below link to full pages; treat your model's manual as final where CD generations differ.
Where CD range fault codes appear
CD-range boilers show E-prefixed codes on a small, simple display (some versions supplement with indicator lights). Note exactly what shows, plus your model designation (CD28C etc.) — it dates the code scheme for whoever attends.
Resetting a Alpha CD range
Press the reset button briefly to clear and retry; pressure faults want a top-up to about 1–1.5 bar first. On boilers this age, resist the serial-reset habit entirely — each fault is information, and wear faults reset away exactly never.
Common CD range problems
Late-life CDs present the full senior-boiler repertoire: ignition-component wear and winter condensate trouble, overheats as pumps and heat exchangers labour under years of scale and sludge, sensors and fans reaching honest ends. Individually cheap fixes; collectively, a conversation about the boiler's future worth having before mid-winter has it for you.
Most common CD range fault codes
- E1 Alpha boilers display two closely related fault codes that are often confused: E1 and… Read more →
- E2 The E2 fault code on an Alpha boiler means the boiler has tried to light the burner but… Read more →
- E5 The E5 code on an Alpha boiler signals that the primary flow NTC thermistor — the sensor… Read more →
- E10 The E10 fault code on Alpha boilers is triggered when the boiler detects that system… Read more →