Halstead Ace Fault codes & diagnostics

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

Combi Natural Gas 24 kW 2000-2005 Discontinued
GC Numbers 41-333-7747-333-10

Replaced by: Ace High

Download the Halstead Ace manualThe official installation and service manual (PDF), the document these fault codes were read from. PDF

The fault code is already on your display

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

All 5 documented codes

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Activate

Your boiler has failed to ignite and cannot establish a flame, likely because it is not properly recognising its internal control settings or requires a part replacement.

High Engineer only £180-350

Parts commonly replaced

  • BCC (Boiler Control Card)
  • Ignition lead
  • Spark generator
Ignition Lock-out

Your boiler has stopped working because it failed to light the flame, so it has purposefully shut down for safety.

High Engineer only £120-250

Parts commonly replaced

  • Ignition electrode
  • Gas valve
  • Printed Circuit Board (PCB)
Ignition lockout

Your boiler has stopped working because it failed to light the flame, which often happens due to a simple supply issue or a temporary glitch.

High Engineer only £120-250

Parts commonly replaced

  • Ignition electrode
  • Gas valve
  • Printed Circuit Board (PCB)
Overheat thermostat

Your boiler has automatically turned itself off because it got too hot, likely to prevent internal damage or overheating.

High Engineer only £120-250

Parts commonly replaced

  • Overheat thermostat
  • Pump
  • Diverter valve
  • System filter
Safety Lock-out LED

Your boiler has stopped working because it failed to light or has become too hot, causing a safety shutdown to protect your home.

High Engineer only £120-250

Parts commonly replaced

  • Ignition electrode
  • Gas valve
  • Overheat thermostat
  • Printed Circuit Board (PCB)

2 operating states & engineer diagnostics

Not faults — these are normal operating states. Tap to expand.