Commercial Gas Engineering Knowledge Base
Answers to real engineering questions — testing and purging, pressure, pipe sizing and plant — written by working Gas Safe commercial engineers.
Strength testing, tightness testing, purging, commissioning and decommissioning of commercial gas installations under IGEM/UP/1 and IGEM/UP/1A.
- What Is IGEM/UP/1? Commercial Gas Testing & Purging Standard
- What Is IGEM/UP/1A? Small Commercial Gas Installations
- Commercial Gas Tightness Testing Procedure, Step by Step
- Strength Test vs Tightness Test: What Is the Difference?
- Commercial Gas Purging Explained
- Direct Purging vs Indirect Purging
- Purging Into Service: Commissioning Commercial Gas Pipework
- Purging Out of Service: Decommissioning Commercial Gas Pipework
- Calculating Gas Installation Volume
- Commercial Gas Pipework Commissioning: The Full Sequence
- When Is Nitrogen Purging Required?
- Testing Large Commercial Gas Installations
- Gas Tightness Testing: What Happens and How Long It Takes
Working pressure, pressure loss, regulators, governors, boosters, pipe sizing and diversity for commercial gas installations.
- Commercial Gas Working Pressure Explained
- Gas Inlet Pressure vs Burner Pressure
- Causes of Low Gas Pressure on Commercial Installations
- Commercial Gas Pressure Drop: How Much Is Acceptable?
- Maximum Permissible Pressure Loss in Gas Pipework
- Commercial Gas Pipe Sizing Calculations
- Diversity Calculations for Commercial Gas
- How to Calculate Gas Consumption from kW
- Gas Meter Pressure Problems
- Gas Governor Faults: Symptoms and Diagnosis
- How Commercial Gas Regulators Work
- How a Commercial Gas Booster Works
Certificates, inspections and legal duties for commercial gas installations.
Engineering diagnosis of commercial boiler faults: ignition and flame failure, lockouts, overheating, sensors, fans, gas valves, flues, condensate, pressure and combustion.
- Commercial Boiler Ignition Failure: Causes & Diagnosis
- Commercial Boiler Flame Failure Explained
- Boiler Locks Out After Ignition: Why It Happens
- Flame Loss During Operation on Commercial Boilers
- Commercial Boiler Overheating: Causes & Fixes
- Blocked Commercial Boiler Heat Exchanger
- High Differential Temperature (ΔT) on a Commercial Boiler
- Low Differential Temperature on a Commercial Boiler
- Low System Pressure on Commercial Boilers
- High System Pressure on Commercial Boilers
- Commercial Boiler Short Cycling
- Commercial Boiler Fan Fault
- Commercial Boiler Gas Valve Fault
- Boiler Ignition Electrode Fault
- Boiler Ionisation (Flame Sensing) Fault
- Commercial Boiler Flue Fault
- Commercial Boiler Condensate Fault
- Commercial Boiler PCB Fault
- Commercial Boiler Pump Fault
- Boiler Flow Sensor Fault
- Boiler Return Sensor Fault
- Boiler High-Limit Thermostat Fault
- Poor Combustion Readings on Commercial Boilers
- High CO Readings on Commercial Boilers
- Incorrect CO/CO₂ Ratio: What It Means
Fault diagnosis and operation of commercial boilers and plant.
Interlocks, ventilation and gas safety in commercial kitchens.
Gas Safe registration for commercial work, ACS commercial categories, and how to check a commercial gas engineer is qualified for the job.
The main types of commercial gas appliances — boilers, burners, warm air and radiant heaters, catering equipment, water heaters and CHP — and what each needs from the installation.
Types and sizes of commercial gas meters — diaphragm, rotary, turbine and ultrasonic — meter installations, regulators, volumes and who is responsible for what.
The test equipment and tools a commercial gas engineer uses — pressure gauges, flue gas analysers, gas detectors, purge kit and pipework tools — and why calibration matters.
Fault code lists for commercial boilers and water heaters — Ideal Evomax 2, Hamworthy, Remeha, Andrews, Lochinvar and Rinnai — plus guides to burner lockouts, gas valve, ignition and gas meter faults.
- Ideal Evomax 2 Fault Codes (1–99) Explained
- Hamworthy Fault Codes: Wessex ModuMax mk3/mk4, Upton, Stratton mk2, Varmax
- Hamworthy Fault Codes: Purewell VariHeat, Fleet, Stratton mk1, Wessex ModuMax mk2
- Hamworthy Dorchester DR-FC Evo Water Heater Fault Codes
- Remeha Gas 210 Eco Pro Fault Codes (E:00–E:39)
- Remeha Quinta Pro Fault Codes (E00–E40)
- Andrews MAXXflo Water Heater Fault Codes
- Rinnai Infinity Water Heater Fault Codes (11, 12, LC)
- Lochinvar EcoSword Water Heater Fault Codes
- Commercial Burner Lockout: Causes and What To Do
- Commercial Gas Valve Faults
- Commercial Gas Boiler Ignition Faults
- Commercial Gas Meter Faults: Who To Call