Halstead iHeat 24c Fault codes & diagnostics

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

Combi Natural Gas 24 kW 2008 onwards Discontinued
GC Number 47-260-19
Download the Halstead iHeat 24c manual The official installation & service manual (PDF) — the exact document these fault codes were verified against. PDF

This boiler uses LED flash patterns

Count the flashes in one repeating group before the pause. That number is your fault code. Do not reset until you have noted it. How to read fault codes →

Versions & GC numbers

Which version do you have?

The GC number on your boiler's data badge identifies the exact appliance and production years, as recorded in the UK Product Characteristics Database.

GC number Appliance (register name) Produced
47-260-19 Iheat 24c 2008–present
Just want the most common Halstead iHeat 24c faults?
The top 6 problems in plain English — with causes, DIY checks and repair costs.
Fault codes

All 4 documented codes

Tap any card for details

Green LED On every 0.5 second

Your boiler has paused temporarily and is waiting for conditions to return to normal before it attempts to start again.

Low DIY-safe £0-120

What to check first

  1. Check if the water pressure is between 1.0 and 1.5 bar
  2. Ensure your gas supply is active (e.g., check other gas appliances)
  3. Wait 15 minutes to see if the boiler resets itself automatically

Parts commonly replaced

  • NTC Temperature Sensor
  • Water Pressure Switch

Related codes

Full explanation for Green LED On every 0.5 second
Red LED On permanently

Your boiler has switched itself off because it has become too hot to operate safely.

High DIY-safe £100-£350

What to check first

  1. Check that all radiator valves are fully open to allow water to flow.
  2. Ensure there is enough pressure in the system by checking the gauge is between 1.0 and 1.5 bar.
  3. Wait 30 minutes for the unit to cool down and then press the reset button.

Parts commonly replaced

  • Circulation pump
  • Overheat thermostat
  • Main Heat Exchanger

Related codes

Full explanation for Red LED On permanently
Status & diagnostic codes

3 operating states & engineer diagnostics

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

Green LED Flashing 8-times every second Status Your boiler has entered an automatic management mode to optimize the temperature of your heating system and is not currently reporting a hardware fault. Green LED Flashing every 6-seconds Status Your boiler is working correctly and is simply sitting in standby mode waiting for you to turn on the heating or hot water. Yellow LED On every 0.5 second Diagnostic Your boiler is currently stuck in a professional testing mode, which is usually only used by engineers to check for proper combustion.