Grant Vortex Blue / Vortex Outdoor Fault codes & diagnostics

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

SystemRegularOil Oil 15-70 kW 2014-present

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Note it down before pressing reset — resetting clears the code immediately. How to read fault codes →

Just want the most common Grant Vortex Blue / Vortex Outdoor faults?
The top 6 problems in plain English — with causes, DIY checks and repair costs.
Fault codes

All 4 documented codes

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10

Your boiler system is leaking fuel or fumes, which is causing a noticeable smell of heating oil around the unit.

Emergency Engineer only £100-250

Parts commonly replaced

  • Fuel line seals
  • Flexible oil hose
  • Copper compression fittings
  • Oil filter gasket
Full explanation for 10
Burner Lock-out

Your boiler's safety system has detected a problem with the burner and has shut the unit down to prevent damage or unsafe operation.

High DIY-safe £120-280

What to check first

  1. Check that you have enough oil in your storage tank.
  2. Ensure the oil supply valve is fully open.
  3. Wait one minute, then press the illuminated reset button on the burner cover once only.

Parts commonly replaced

  • Oil nozzle
  • Photocell
  • Oil pump
  • Fuel filter
Full explanation for Burner Lock-out
lock-out

Your boiler is starting up briefly but then shutting itself down because it cannot maintain a stable flame.

High DIY-safe £120-280

What to check first

  1. Check that you have sufficient heating oil in your storage tank
  2. Ensure the oil supply valves are fully open
  3. Press the illuminated reset button on the burner once only

Parts commonly replaced

  • Photocell (Flame sensor)
  • Oil nozzle
  • Fuel pump
  • Oil filter
Full explanation for lock-out
Safety thermostat

Your boiler has switched itself off because its internal temperature has become too hot, triggered by a safety sensor to protect the system.

High DIY-safe £90-180

What to check first

  1. Locate the high-limit thermostat reset button, which is usually found behind the front casing or under a small plastic screw cap.
  2. Press the button firmly once to reset the safety switch.
  3. Check that your radiator valves are open and that the system pressure is between 1.0 and 1.5 bar.

Parts commonly replaced

  • Safety Limit Thermostat
  • Circulation Pump
  • Control Thermostat
Full explanation for Safety thermostat