Common problems guide

The most common Firebird Envirogreen problems

The faults most likely to send a Firebird Envirogreen into lockout — with plain-English causes, what to check first, estimated repair costs and whether you need a Gas Safe engineer.

26 documented codes
6 most common
5 DIY-safe checks
1 engineer needed

The 6 most common faults

01
e5 High DIY-safe

Your boiler's burner has shut itself down for safety and requires a manual restart to try and restore heating and hot water.

What to try first

Locate the red reset button on the burner itself (behind the front casing)Press the reset button once to see if the burner fires upCheck that you have enough oil in your storage tank

Est. cost
£100-250
Parts
Photocell, Oil nozzle, Oil pump
Full guide for e5
02
High limit High DIY-safe

Your boiler has reached an unsafe temperature and has automatically shut down to prevent damage.

What to try first

Wait for the boiler to cool down completely (at least 20-30 minutes).Ensure all radiator valves are fully open and there are no blockages in the system.Locate the manual reset button (usually under a black screw cap) and press it firmly.

Est. cost
£90-250
Parts
High limit thermostat, Circulation pump, Temperature thermistor
Full guide for High limit
03
Burner lockout High DIY-safe

Your boiler has stopped running as a safety precaution because it couldn't successfully light or maintain a flame.

What to try first

Check that you have enough heating oil in your tank.Ensure the oil supply valve is fully open.Press the illuminated reset button on the burner control box once.

Est. cost
£120-280
Parts
Oil nozzle, Photocell, Oil pump
Full guide for Burner lockout
04
L2 High DIY-safe

Your boiler has stopped running because it has locked itself out, usually because it can't draw enough oil or light the flame.

What to try first

Check that you have enough oil in your storage tankEnsure the oil supply valve is fully openPress the illuminated reset button on the burner once

Est. cost
£120-280
Parts
Oil nozzle, Photocell, Fuel pump
Full guide for L2
05
SAFETY HIGH LIMIT THERMOSTAT High DIY-safe

Your boiler has switched itself off because it got too hot, acting as a safety measure to prevent damage.

What to try first

Wait for the boiler to cool down completely (at least 20-30 minutes).Locate the manual reset button for the high limit thermostat, usually found under a black screw cap on the control panel.Unscrew the cap and firmly press the small reset button inside.Restart the boiler and check that your radiator valves are open and the pump is running.

Est. cost
£90-180
Parts
Overheat Thermostat, Circulating Pump, Control Thermostat
Full guide for SAFETY HIGH LIMIT THERMOSTAT
06
e1 High Engineer

Your boiler's internal temperature sensor is reporting an error, which means the system cannot monitor its own heat levels and has shut down as a precaution.

Est. cost
£90-180
Parts
Flow Thermistor, Return Thermistor, Wiring Harness
Full guide for e1

on the Firebird Envirogreen

PhotocellOil nozzleOil pumpControl boxHigh limit thermostatCirculation pump

Based on parts cited in our fault code database. Your engineer will confirm what's actually needed after diagnosis.

Call a Gas Safe engineer if…

  • You can smell gas or see signs of a leak
  • The Firebird shows an Emergency or High severity code
  • The boiler keeps locking out after repeated resets
  • You've tried the DIY checks and the fault hasn't cleared
  • There's visible water leaking from the boiler
  • The flame is yellow or orange instead of blue

Avoid the next call-out bill

Monthly cover means no unexpected bills when your boiler breaks down.

Approved partner
Domestic Appliance Guard
Unlimited call-outs, 24/7 helpline, no price-hike promise
Get a quote →

Affiliate links. We may earn a commission at no extra cost to you.

See the full 26-code list for the Firebird Envirogreen