Firebird Boiler Fault Codes

21 fault codes across 10 Firebird boiler models — explained in plain English.

Irish manufacturer specialising in oil boilers. Popular in rural UK and Ireland.

21 fault codes
10 models documented
6 currently sold
4 legacy models

Firebird fault codes on this site

We document 21 fault codes across 10 Firebird models, covering 10 distinct codes. Firebird boilers use letter-and-number codes such as E1, E5, E2. Codes for 10 of these models are taken directly from the manufacturer's own service or installation manual.

Models covered: Enviro, Popular 15-20, Popular, Envirogreen, Popular Heatpac, Silver Slimline Systempac 2020, Cascading Management Controller, Envirogreen Regular, S Range, Super Q90.

Codes that appear on the most Firebird models:
E2 E1 E5 BURNER LOCKOUT L2 High limit
Just want the most common Firebird problems?
The top 8 faults across the whole Firebird range — causes, DIY checks, repair costs.
Most serious

High-severity Firebird fault codes

E1
Your boiler's internal temperature sensor has stopped working correctly, causing the system to shut down for safety.
Enviro
 E5
Your boiler's burner has stopped firing for safety reasons, which means you currently have no heating or hot water.
Enviro
 E2
Your boiler has detected an issue with the sensor that monitors the temperature of the exhaust gases, causing the system to shut down as a safety precaution.
Popular
 E1
Your boiler's temperature sensor is providing faulty information, causing the system to stop operating as a safety precaution.
Envirogreen
 E5
Your oil boiler has safely shut down because the burner has failed to ignite properly.
Envirogreen
All models

10 Firebird boiler models

Enviro
System
2 fault codes · 2013-present
Popular 15-20
Regular Discontinued
0 fault codes
Popular
Regular Discontinued
1 fault codes
Envirogreen
3 fault codes · 2024-present
Popular Heatpac
Regular Discontinued
1 fault codes · 1990-2015
Silver Slimline Systempac 2020
System
6 fault codes · 2020-present
Cascading Management Controller
1 fault codes
Envirogreen Regular
Regular
4 fault codes · 2019-present
S Range
System
1 fault codes · 2010-present
Super Q90
Regular Discontinued
2 fault codes
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