Vokera Linea 28 Fault codes & diagnostics

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

Combi Natural Gas 28 kW 1998 onwards Discontinued
GC Number 47-094-28

Replaced by: Linea HE

Download the Vokera Linea 28 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 →

Severity at a glance

Each cell = one fault code. Hover to identify.
10 High 1 Medium
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
47-094-28 Linea Linea 28 1998–present
Just want the most common Vokera Linea 28 faults?
The top 6 problems in plain English — with causes, DIY checks and repair costs.
Fault codes

All 11 documented codes

Tap any card for details

01

Your boiler has failed to light or maintain a flame, which means it has locked itself out to prevent fuel from building up.

High DIY-safe £100-£350

What to check first

  1. Check if other gas appliances (like a cooker) are working to confirm gas is reaching the property
  2. Turn the selector switch to the 'R' (Reset) position for a few seconds and then back to the 'ON' position
  3. Ensure your gas meter has credit if you are on a pre-payment meter

Parts commonly replaced

  • Ignition Electrode
  • Gas Valve
  • PCB (Printed Circuit Board)

Related codes

Full explanation for 01
02

Your boiler has stopped working because it has gotten too hot or the water is not circulating through the system correctly.

High DIY-safe £120-£350

What to check first

  1. Wait for the boiler to cool down for at least 30 minutes.
  2. Check that all radiator valves and the flow/return valves under the boiler are fully open.
  3. Press the 'Reset' button on the front control panel to restart the unit.

Parts commonly replaced

  • Circulation Pump
  • Overheat Thermostat
  • Limit Thermistor

Related codes

Full explanation for 02
03

Your boiler has detected a blockage or a fault in the system that expels exhaust gases, causing it to shut down for safety.

High Engineer only £100-280

Parts commonly replaced

  • Fan
  • Air Pressure Switch
  • Flue Venturi
  • Venturi Tube

Related codes

Full explanation for 03
04

Your boiler has detected that the water pressure is too low for it to operate safely, which is usually caused by a small leak or air in the system.

High DIY-safe £60-140

What to check first

  1. Check the pressure gauge on the front of the boiler; it should ideally be between 1 and 1.5 bar.
  2. Locate the external filling loop (the silver flexible hose) underneath or near the boiler.
  3. Slowly open the valves on the filling loop until you hear water entering and the needle reaches 1.5 bar, then close them tightly.

Parts commonly replaced

  • Filling loop
  • Pressure sensor
  • Expansion vessel recharge

Related codes

Full explanation for 04
05

Your boiler has lost its connection with the external remote controller, meaning they are unable to talk to each other to manage your heating.

High DIY-safe £90-250

What to check first

  1. Check if the batteries in your RC05 remote control unit need replacing
  2. Ensure the remote control is within range of the boiler and has not been moved
  3. Turn the boiler power off and back on again to try and reset the connection

Parts commonly replaced

  • RC05 Remote Control
  • Receiver PCB
  • Wiring harness

Related codes

Full explanation for 05
06

Your boiler has lost its ability to accurately measure the temperature of your hot water, which may cause it to run poorly or stop providing hot water altogether.

Medium Engineer only £90-160

Parts commonly replaced

  • DHW NTC Thermistor
  • Wiring harness connectors

Related codes

Full explanation for 06
07

Your boiler has lost its ability to accurately measure the water temperature inside the system, which is preventing it from heating up safely.

High Engineer only £90-160

Parts commonly replaced

  • Primary NTC Thermistor
  • Connecting Wiring Loom

Related codes

Full explanation for 07
08

Your boiler has reached an unsafe temperature, causing it to shut down to prevent damage or overheating.

High Engineer only £90-180

Parts commonly replaced

  • Limit Thermostat
  • NTC Sensor
  • Circulation Pump

Related codes

Full explanation for 08
09

Your boiler's internal computer has developed an error and can no longer control the heating system correctly.

High Engineer only £220-450

Parts commonly replaced

  • Main PCB
  • Wiring harness

Related codes

Full explanation for 09
C1

Your boiler's main internal computer has detected a serious technical error and needs to be reset or potentially replaced by a professional.

High Engineer only £250-450

Parts commonly replaced

  • Printed Circuit Board (PCB)
Full explanation for C1
L2

Your boiler has failed to light because it cannot detect a flame, meaning you currently have no heating or hot water.

High Engineer only £120-250

Parts commonly replaced

  • Ignition electrode
  • Gas valve
  • PCB
Full explanation for L2
Status & diagnostic codes

6 operating states & engineer diagnostics

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

flashing red LED Status Your boiler is currently running at a restricted low-power setting designed for testing purposes, which may prevent it from heating your home or water effectively. CO Diagnostic Your boiler is currently set to a special testing mode used by engineers to check its performance, rather than operating in its normal heating mode. JP6 Diagnostic Your boiler's setting that keeps a small amount of warm water ready for immediate use has been accidentally disabled or the internal connection responsible for this feature has come loose. JP8 Diagnostic Your boiler has lost its internal configuration settings, meaning it has forgotten whether it should be running on natural gas or LPG. JP9 Diagnostic Your boiler's internal settings are currently confused because a small configuration plug has been moved or become loose, preventing the heating system from turning on. L1 Status Your boiler is operating normally and there are no active faults.