Grant Vortex Eco External Wall Hung Fault codes & diagnostics

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

System Oil 2008-2015
Download the Grant Vortex Eco External Wall Hung manualThe official installation and service manual (PDF), the document these fault codes were read from. PDF

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Severity at a glance

Each cell = one fault code. Hover to identify.
1 Emergency 4 High 1 Medium
Just want the most common Grant Vortex Eco External Wall Hung faults?
The top 6 problems in plain English — with causes, DIY checks and repair costs.
Fault codes

All 6 documented codes

Tap any card for details

1

Your boiler is trying to fire up for heating or hot water, but the burner isn't catching.

High DIY-safe £100-250

What to check first

  1. Check your oil supply to ensure you have not run out of heating oil.
  2. Verify that the oil supply valve to the boiler is fully open.
  3. Press the reset button on the burner control box once to see if it restarts.

Parts commonly replaced

  • Photocell
  • Oil burner nozzle
  • Control box
  • Ignition electrodes

Related codes

Full explanation for 1
2

Your boiler is trying to fire up for heating or hot water, but the burner isn't catching, so it has safely locked itself out.

High Engineer only £100-250

Parts commonly replaced

  • Photocell / flame detector
  • Oil burner nozzle
  • Control box

Related codes

Full explanation for 2
3

Your boiler is trying to fire up, but the oil burner is failing to catch a flame and is shutting down for safety.

High DIY-safe £100-£250

What to check first

  1. Check your oil tank to ensure you have not run out of heating oil.
  2. Locate the lockout reset button on the burner, press it once firmly, and wait to see if the boiler restarts.
  3. Check if any oil supply valves or fire valves have been accidentally tripped or closed.

Parts commonly replaced

  • Photocell (Flame detector)
  • Oil nozzle
  • Ignition electrodes
  • Control box

Related codes

Full explanation for 3
4

Your boiler's burner tries to start up, but it immediately gives up and shuts down for safety.

High Engineer only £100-£250

Parts commonly replaced

  • Photocell / flame detector
  • Oil burner control box
  • Nozzle or oil filter

Related codes

Full explanation for 4
5

Your boiler is struggling to light smoothly, resulting in a loud bang or rumble when the flame finally catches.

Emergency Engineer only £150-300

Parts commonly replaced

  • Oil burner nozzle
  • Ignition electrodes
  • Photocell
  • Oil pump

Related codes

Full explanation for 5
6

Your boiler is repeatedly switching itself on and off instead of staying lit to heat your home.

Medium Engineer only £120-250

Parts commonly replaced

  • Thermostat
  • Control board
  • Oil pump
  • Flame detector

Related codes

Full explanation for 6
Status & diagnostic codes

1 operating states & engineer diagnostics

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

21.0 Diagnostic Your boiler is currently running at its maximum designed heat output, which is a status message rather than a breakdown of the appliance.
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