Ideal Esprit HE 35 Fault codes & diagnostics

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

Combi Natural Gas 2007-2010 Discontinued
GC Number 47-348-48
Download the Ideal Esprit HE 35 manualThe official installation and service manual (PDF), the document these fault codes were read from. PDF
Other editions of this manual (the one above is UIN 203642 A06): UIN 203642 A02 (PDF) Manufacturers revise a model over the years. If your boiler is older than the manual above, an earlier edition may match it better.

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Severity at a glance

Each cell = one fault code. Hover to identify.
11 High

All 11 documented codes

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86

Your boiler's main electronic brain has encountered an internal communication error and has safely shut down to prevent unexpected behavior.

High Engineer only £200-£400

Parts commonly replaced

  • Printed Circuit Board (PCB)
  • Wiring harness

Related codes

87

Your boiler has temporarily stopped working because it has gotten too hot inside, usually due to a blockage or restricted water flow.

High Engineer only £150-300

Parts commonly replaced

  • Heat Exchanger
  • Pump
  • NTC Thermistor

Related codes

88

Your boiler has temporarily stopped working because it has detected a problem with the internal water pressure.

High Engineer only £90-180

Parts commonly replaced

  • Water pressure switch
  • Pressure switch wiring harness

Related codes

89

Your boiler has stopped working because it cannot detect that the internal fan, which safely removes harmful combustion gases, is operating properly.

High Engineer only £150-300

Parts commonly replaced

  • Flue Fan
  • Air Pressure Switch
  • Printed Circuit Board (PCB)

Related codes

90

Your boiler has temporarily stopped working because it cannot accurately read the temperature of the water flowing through the system.

High Engineer only £120-£250

Parts commonly replaced

  • Flow Thermistor
  • Wiring Harness

Related codes

94

Your boiler is trying to start but cannot detect that the burner has successfully lit, so it has shut itself down to keep you safe.

High Engineer only £150-300

Parts commonly replaced

  • Ignition electrode
  • Flame rectification probe
  • PCB
95

Your boiler is failing to start because it is not sensing the correct electrical connection path from your home's power supply.

High Engineer only £120-250

Parts commonly replaced

  • Printed Circuit Board (PCB)
  • Wiring Harness

Related codes

H9

Your boiler has temporarily stopped working because it has detected an unusually low temperature inside its main heating unit.

High Engineer only £150-300

Parts commonly replaced

  • NTC Thermistor
  • Flow and Return Sensor
  • Printed Circuit Board (PCB)

Related codes

H9/L9

Your boiler has detected that it is getting dangerously hot and has shut itself down to prevent any internal damage.

High Engineer only £150-350

Parts commonly replaced

  • Pump
  • Heat exchanger
  • Temperature sensor

Related codes

L9

Your boiler has temporarily stopped working because it has detected that a part inside has become too cold, so it has safely shut down to protect itself.

High Engineer only £150-300

Parts commonly replaced

  • NTC thermistor
  • Flow sensor
  • Main printed circuit board (PCB)

Related codes

LE

Your boiler has stopped working because the water pressure inside the system has dropped too low.

High DIY-safe

What to check first

  1. Locate the filling loop underneath your boiler.
  2. Open the valves slowly to let water into the system until the pressure gauge reaches between 1 and 1.5 bar.
  3. Close the valves firmly and press the reset button on your boiler.

Parts commonly replaced

  • Filling loop
  • Pressure relief valve
  • Pressure sensor

Related codes