Heatline Sargon Fault codes & diagnostics

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

Combi Natural Gas 24-35 kW 2008-2009 Discontinued
GC Number 47-157-15

Replaced by: Capriz

Download the Heatline Sargon manual The official installation & service manual (PDF) — the exact document these fault codes were verified against. PDF

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Severity at a glance

Each cell = one fault code. Hover to identify.
2 Emergency 20 High

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
47-157-15 Sargon 24 2008–2009

All 22 documented codes

Tap any card for details

10

Your boiler is struggling to clear exhaust gases safely because it cannot confirm that the internal fan is moving air properly, so it has shut down to prevent unsafe operation.

High Engineer only £150-250

Parts commonly replaced

  • Air pressure switch
  • Flue fan unit
  • Venturi tube

Related codes

12

Your boiler is attempting to light but failing to stay on, meaning you currently have no heating or hot water.

High Engineer only £150-300

Parts commonly replaced

  • Gas valve
  • Ignition electrode
  • PCB

Related codes

13

Your boiler is struggling to clear exhaust gases safely, so it has turned itself off to prevent a build-up of fumes.

High Engineer only £120-250

Parts commonly replaced

  • Air pressure switch
  • Flue fan
  • Venturi tube

Related codes

14

Your boiler is struggling to clear exhaust gases out through the flue, so it has safely shut down to prevent any risk of fumes entering your home.

High Engineer only £120-250

Parts commonly replaced

  • Air pressure switch
  • Flue fan
  • Venturi nozzle

Related codes

15

Your boiler has stopped working because it cannot safely clear waste gases through the flue.

High Engineer only £180-350

Parts commonly replaced

  • Fan unit
  • Wiring harness
  • Printed Circuit Board (PCB)

Related codes

16

Your boiler has stopped working because it cannot properly clear exhaust gases, which has triggered a safety shutdown to prevent dangerous fumes from building up.

High Engineer only £150-300

Parts commonly replaced

  • Fan assembly
  • Fan harness/wiring
  • Printed Circuit Board (PCB)
17

Your boiler has stopped working because it cannot properly clear exhaust gases, which is a key safety feature to prevent fumes from building up inside.

High Engineer only £180-350

Parts commonly replaced

  • Fan assembly
  • Printed Circuit Board (PCB)
  • Venturi

Related codes

18

Your boiler is struggling to clear exhaust fumes safely, so it has stopped working to prevent any risk of harmful gases building up.

High Engineer only £120-250

Parts commonly replaced

  • Air pressure switch
  • Flue fan
  • Venturi tube
19

Your boiler is struggling to clear exhaust gases safely, so it has turned itself off to prevent any risk of fumes entering your home.

Emergency Engineer only £150-300

Parts commonly replaced

  • Air pressure switch
  • Flue assembly
  • Fan

Related codes

20

Your boiler is failing to ignite because it cannot receive or burn the gas supply it needs to produce heat.

Emergency Engineer only £120-250

Parts commonly replaced

  • Gas valve
  • Ignition electrode
  • PCB
Showing 11–20 of 22
21

Your boiler is struggling to clear air correctly or regulate its fuel supply, so it has safely shut down to prevent any risk.

High Engineer only £150-300

Parts commonly replaced

  • Fan
  • Gas valve
  • PCB

Related codes

23

Your boiler has detected an issue with the internal air intake or exhaust system, causing it to shut down for safety reasons.

High Engineer only £180-350

Parts commonly replaced

  • Fan assembly
  • Air pressure switch
  • Wiring harness
24

Your boiler is struggling to clear exhaust gases properly, so it has safely shut down to prevent any risk of fumes entering your home.

High Engineer only £120-250

Parts commonly replaced

  • Air pressure switch
  • Flue fan
  • Venturi assembly

Related codes

25

Your boiler is failing to light or stay lit, meaning it cannot produce heat or hot water.

High Engineer only £150-350

Parts commonly replaced

  • Ignition electrode
  • Gas valve
  • Flame sensing probe
26

Your boiler has detected that the internal fan responsible for safely removing exhaust gases is not spinning at the required speed.

High Engineer only £180-300

Parts commonly replaced

  • Fan assembly
  • Printed Circuit Board (PCB)
  • Wiring harness
F1

Your boiler has automatically shut itself down because it detected that the internal water temperature has become dangerously high.

High Engineer only £120-250

Parts commonly replaced

  • Overheat thermostat
  • Thermal fuse
  • NTC thermistor
  • Circulation pump

Related codes

F2

Your boiler is having trouble sensing the temperature of the hot water it is producing, so it has shut down to prevent overheating.

High Engineer only £120-180

Parts commonly replaced

  • DHW NTC sensor
  • Wiring harness

Related codes

F3

Your boiler has lost its ability to accurately measure the water temperature, so it has safely shut itself down to prevent overheating.

High Engineer only £120-200

Parts commonly replaced

  • NTC Temperature Sensor
  • Wiring harness

Related codes

F4

Your boiler has failed to start the flame needed to heat your home or water, often because internal waste pipes are clogged or the ignition system isn't sparking correctly.

High Engineer only £120-250

Parts commonly replaced

  • Ignition Electrode
  • Condensate Trap
  • Printed Circuit Board

Related codes

F5

Your boiler has detected a fault with a safety sensor that monitors the temperature of the gases leaving the flue, causing it to shut down to prevent potential overheating.

High Engineer only £120-200

Parts commonly replaced

  • Flue gas temperature sensor
  • Wiring harness

Related codes

Showing 21–22 of 22
F8

Your boiler has detected that the internal fan responsible for safely removing exhaust gases is not spinning at the correct speed, so it has shut down to keep your home safe.

High Engineer only £180-350

Parts commonly replaced

  • Fan assembly
  • Printed Circuit Board (PCB)
  • Venturi

Related codes

F9

Your boiler has detected that the internal exhaust fan is spinning when it should be switched off, which prevents the system from starting safely.

High Engineer only £150-250

Parts commonly replaced

  • Fan assembly
  • Printed Circuit Board (PCB)
  • Wiring harness

Related codes