Lesson 5: Simple Electrical Fixes - Cheat Sheet
Electrical Safety Essentials
Safety Rule | Why It Matters | How to Implement |
Turn off power | Prevents electrical shock | Switch off appropriate circuit breaker |
Test before touching | Confirms power is off | Use non-contact voltage tester on wires/connections |
Use insulated tools | Secondary protection | Look for tools rated for electrical work |
Wear rubber-soled shoes | Prevents grounding through body | No wet areas, no bare feet |
One hand rule | Prevents current across heart | Keep one hand in pocket when testing |
No metal jewelry | Prevents accidental conductivity | Remove rings, watches, bracelets |
Never work when tired | Prevents mistakes | Only work when alert and focused |
Proper lighting | Helps see connections clearly | Use headlamp or work light |
UK Electrical System Basics
Component | Standard UK Specification | Notes |
Voltage | 230V AC | Much higher than US 120V - more dangerous |
Frequency | 50Hz | US uses 60Hz |
Domestic circuits | 6A, 16A, 32A typically | Different breaker sizes for different purposes |
Socket outlets | 13A, three-pin | Includes built-in fuse |
Lighting circuits | 6A or 10A | Separate from power circuits |
Ring circuits | 32A | Powers most sockets in UK homes |
Radial circuits | 20A or 32A | For high-power appliances |
Earth system | TT, TN-S, or TN-C-S | Varies by property age and location |
Wire Color Codes (Post-2004 UK Standard)
Wire | Color | Function | Common Connections |
Live | Brown | Carries current to device | Marked “L”, brass screws, red switches |
Neutral | Blue | Returns current to source | Marked “N”, silver screws |
Earth | Green/Yellow | Safety ground | Marked “E” or ⏚, green screws |
Wire Color Codes (Pre-2004 UK Standard)
Wire | Old Color | New Color | Function |
Live | Red | Brown | Carries current to device |
Neutral | Black | Blue | Returns current to source |
Earth | Green/Yellow | Green/Yellow | Safety ground |
Essential Electrical Tools
Tool | Purpose | Estimated Cost | Priority |
Non-contact voltage tester | Verify power is off | £8-15 | Essential |
Insulated screwdrivers | Safe removal of electrical fixtures | £10-20 set | Essential |
Wire strippers | Remove insulation from wires | £8-15 | High |
Needle-nose pliers | Bend and position wires | £8-12 | High |
Electrical tape | Insulate connections | £2-5 | Essential |
Circuit finder | Identify which breaker controls circuit | £15-30 | Medium |
Multimeter | Test voltage, continuity, resistance | £20-50 | Medium |
Cable detector | Locate wires in walls | £20-40 | Medium |
Light Switch Types
Type | Identification | Common Uses | Replacement Cost |
Single-pole | One switch controls light | Most common room lighting | £3-10 |
Two-way | Two switches control same light | Hallways, stairs | £5-15 each |
Intermediate | Three+ switches control same light | Large rooms with multiple entries | £8-20 each |
Dimmer | Adjustable brightness control | Living areas, dining rooms | £10-30 |
Timer | Includes timing function | Bathroom fans, outdoor lights | £15-40 |
Smart switch | WiFi/Bluetooth connectivity | Any room for automation | £20-60 |
Outlet Types
Type | Identification | Common Uses | Replacement Cost |
Standard 13A | Regular 3-pin socket | Most appliances and devices | £2-10 |
Switched | Includes on/off switch | Energy saving, safety | £5-15 |
USB | Includes USB charging ports | Bedrooms, home offices | £15-30 |
RCD protected | Has test button | Kitchens, bathrooms, outdoors | £15-40 |
Outdoor | Weatherproof cover | Gardens, exterior walls | £10-30 |
Shaver | Smaller specialized outlet | Bathrooms | £15-30 |
Light Fixture Types
Type | Mounting Method | Wiring Complexity | Replacement Difficulty |
Ceiling pendant | Ceiling rose or bracket | Simple (3 wires) | Easy |
Flush mount | Directly to ceiling box | Simple (3 wires) | Easy |
Recessed/Downlight | Into ceiling cavity | Moderate | Moderate |
Track lighting | Rail system | Complex | Moderate-Difficult |
Wall sconce | Wall mounting bracket | Simple (3 wires) | Easy |
Chandelier | Ceiling bracket | Simple but heavy | Moderate (weight) |
Common Electrical Problems and Solutions
Problem | Possible Causes | DIY Solutions | When to Call Pro |
Flickering lights | Loose bulb, loose wiring, circuit overload | Tighten bulb, check switch wiring | If persists after basic checks |
Dead outlet | Tripped breaker, tripped RCD, loose connection | Reset breaker/RCD, check connections | If reset doesn’t work |
Warm outlet/switch | Overloaded circuit, loose connection | Reduce load, check for loose wires | If warm when not loaded |
Tripping breaker | Circuit overload, short circuit, ground fault | Redistribute devices to other circuits | Frequent trips without overload |
Buzzing sound | Loose wiring, dimmer issue | Tighten connections, replace dimmer | Persistent buzzing after checks |
Light bulbs burning out quickly | Wrong wattage, vibration, voltage issue | Use correct wattage, check for loose connections | If persists with correct bulbs |
Replacing a Light Switch - Quick Guide
- Turn off power at breaker
- Test with voltage tester
- Remove cover plate
- Remove switch mounting screws
- Pull switch out carefully
- Note wire connections (photo recommended)
- Disconnect wires
- Connect wires to new switch in same configuration
- Mount new switch in wall box
- Attach cover plate
- Restore power and test
Replacing an Outlet - Quick Guide
- Turn off power at breaker
- Test with voltage tester
- Remove cover plate
- Remove outlet mounting screws
- Pull outlet out carefully
- Note wire connections (photo recommended)
- Disconnect wires
- Connect wires to new outlet in same configuration:
- Brown (red) to brass terminal (L)
- Blue (black) to silver terminal (N)
- Green/yellow to green terminal (E)
- Mount new outlet in wall box
- Attach cover plate
- Restore power and test
UK Building Regulations for Electrical Work
Zone | Description | DIY Permitted? | Certification Required? |
General areas | Living rooms, bedrooms, hallways | Yes, for like-for-like replacements | No, if simple replacements |
Kitchen | Within 60cm of sink | Limited DIY | Yes, Part P notification |
Bathroom | Entire room | Very limited DIY | Yes, Part P notification |
Outdoors | External wiring | Limited DIY | Yes, Part P notification |
New circuits | Adding circuits to consumer unit | No DIY | Yes, must use registered electrician |
Consumer unit work | Any modifications | No DIY | Yes, must use registered electrician |
Professional vs. DIY Decision Guide
Task | DIY Appropriate? | Skill Level | Tools Needed | Time Required |
Replace light switch | Yes | Beginner | Basic | 30 minutes |
Replace standard outlet | Yes | Beginner | Basic | 30 minutes |
Replace light fixture | Yes | Beginner-Intermediate | Basic | 1-2 hours |
Install ceiling fan | Yes | Intermediate | Basic + support | 2-3 hours |
Add new outlet | No | Advanced | Specialized | 2-4 hours |
Install new circuit | No | Professional | Specialized | 4+ hours |
Upgrade consumer unit | No | Professional | Specialized | 4+ hours |
Outdoor wiring | No | Professional | Specialized | Varies |