Firebird Popular Heatpac Fault codes & diagnostics

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

RegularOil Oil 12-100 kW 1990-2015 Discontinued

Replaced by: Enviromax Heatpac

The fault code is already on your display

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

Just want the most common Firebird Popular Heatpac faults?
The top 6 problems in plain English — with causes, DIY checks and repair costs.
Fault codes

All 4 documented codes

Tap any card for details

lock-out

Your boiler's burner has shut itself down because it is struggling to draw fuel, likely due to air or debris blocking the internal pump.

High DIY-safe £120-280

What to check first

  1. Locate the red reset button on the burner control box
  2. Press the button once to see if the burner restarts
  3. Check that you have sufficient heating oil in your storage tank

Parts commonly replaced

  • Oil pump
  • Oil nozzle
  • Oil filter element
Full explanation for lock-out
Lock-out lamp

Your boiler has shut down to protect itself and needs to be manually restarted because the burner has failed to light.

High DIY-safe £100-250

What to check first

  1. Wait for at least 60 seconds after the boiler has stopped.
  2. Locate the red reset button on the burner control box.
  3. Press the reset button once to attempt a restart.
  4. Check that you have sufficient heating oil in your tank.

Parts commonly replaced

  • Oil nozzles
  • Photocell
  • Oil pump
  • Ignition transformer
Full explanation for Lock-out lamp
Overheat

Your boiler has become too hot and has automatically shut down for safety.

High DIY-safe £90-180

What to check first

  1. Wait for the boiler to cool down completely.
  2. Unscrew the black plastic cap on the control panel to reveal the reset button.
  3. Press the manual reset button firmly and replace the cap.
  4. Ensure your radiator valves are open and the system pressure is correct.

Parts commonly replaced

  • Overheat Thermostat
  • Circulating Pump
  • Thermistor
Full explanation for Overheat
RED light

Your boiler's burner has shut down for safety because it couldn't light properly or lost its flame during operation.

High DIY-safe £100-250

What to check first

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

Parts commonly replaced

  • Oil nozzle
  • Photo-electric cell
  • Oil pump
  • Flexible fuel hose
Full explanation for RED light