Vokera Sabre 35HE Fault codes & diagnostics

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

Combi Natural Gas 35 kW 2019-present
GC Number 47-094-72
Download the Vokera Sabre 35HE manualThe official installation and service manual (PDF), the document these fault codes were read from. 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 →

Severity at a glance

Each cell = one fault code. Hover to identify.
2 High 2 Medium 5 Low
Just want the most common Vokera Sabre 35HE faults?
The top 6 problems in plain English — with causes, DIY checks and repair costs.
Fault codes

All 9 documented codes

Tap any card for details

LED / flash-pattern codes
Flashing 8-times a second

Your boiler is currently protecting itself by performing a self-check on the water temperature sensors to ensure it is heating safely.

Low Engineer only £100-200

Parts commonly replaced

  • NTC Sensor
  • PCB
Full explanation for Flashing 8-times a second
Digital codes
DHW NTC fault

Your boiler is struggling to accurately detect the temperature of the water being heated for your taps, which means it may fail to provide hot water or heat it to the wrong temperature.

Medium Engineer only £120-200

Parts commonly replaced

  • Domestic Hot Water (DHW) NTC Thermistor
Full explanation for DHW NTC fault
ON every 0.5-secs (Green LED)

Your boiler is pausing temporarily due to a minor safety check, such as a drop in system water pressure or a momentary blocked air signal.

Low DIY-safe

What to check first

  1. Check the pressure gauge on the front of your boiler to ensure it is sitting between 1 and 1.5 bar.
  2. If the pressure is below 1 bar, use the filling loop underneath the boiler to top it back up.
  3. Turn the boiler off and on again at the mains switch to reset the temporary fault.

Parts commonly replaced

  • Air Pressure Switch
  • Pressure Relief Valve
  • Filling Loop

Related codes

Full explanation for ON every 0.5-secs (Green LED)
ON every 0.5-secs (Red LED)

Your boiler has detected a critical internal safety fault and has locked itself down to prevent damage, meaning it will not provide any heating or hot water until a professional engineer repairs it.

High Engineer only £120-300

Parts commonly replaced

  • Pressure switch
  • Fan assembly
  • Limit thermostat
  • PCB
Full explanation for ON every 0.5-secs (Red LED)
Solid (Red LED)

Your boiler has stopped working because it can no longer accurately read the temperature of the water inside the heating system.

High Engineer only £120-220

Parts commonly replaced

  • Primary NTC sensor
  • Wiring harness
Full explanation for Solid (Red LED)
Solid (Yellow LED)

Your boiler is struggling to accurately measure the temperature of your hot water, which means it may fail to provide hot water or heat it to the wrong temperature.

Medium Engineer only £120-200

Parts commonly replaced

  • DHW NTC thermistor
  • Wiring harness
Full explanation for Solid (Yellow LED)
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