Who are these guides for?
UK electricians and gas engineers — apprentices through to experienced tradespeople. The focus is on-the-job reference: what a code means, how a test is done, and the numbers behind the standard.
Electrical & gas guides for the job
37 practical guides for UK electricians and gas engineers — from EICR codes and BS 7671 testing to boiler commissioning and gas compliance. Get the answer, then move straight into the right calculator or certificate.
Electrical guides
EICR & certification
Observation codes, condition reports and getting the paperwork right.
Inspection & testing
Testing sequence, loop impedance, fault-finding and the numbers behind BS 7671.
- Initial Verification: The BS 7671 Testing Sequence
- RCD Keeps Tripping: Causes and Fixes
- Max Zs Values Table (BS 7671 18th Edition)
- How to Test R1+R2 on a Ring Main
- What Is Prospective Fault Current (PFC)?
- How to Calculate Maximum Demand (with Diversity)
- Safe Isolation Procedure
- Insulation Resistance Testing
- Cable Sizing to BS 7671
Earthing & protection
Earthing arrangements, bonding, and the protective devices behind BS 7671.
Gas guides
Boilers & heating
Commissioning, gas rating, sealed systems and hot water storage.
- Flue Gas Analysis and Combustion Ratios
- Boiler Fault Finding: A Systematic Approach
- Powerflushing a Central Heating System
- S-Plan and Y-Plan Heating Controls
- Gas Pipe Sizing for Domestic Installations
- How to Gas Rate a Boiler
- Expansion Vessel Sizing for Sealed Systems
- The Benchmark Certificate and Boiler Warranties
- Boiler Flue Regulations and Clearances
- Unvented Cylinder (G3) Requirements
Gas safety & compliance
Landlord records, tightness testing and staying registered and compliant.
Every guide, A to Z
The full library — all 37 guides in one index.
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Guides hub FAQs
Are the guides free?
Yes, every guide is free to read. Many link straight into a related free calculator or the certificate you would issue next, so you can move from reading to doing.
Do you cover both electrical and gas?
Yes. Electrical guides cover EICR codes, inspection and testing to BS 7671. Gas guides cover boiler commissioning, sealed systems, and gas safety and compliance.