Portable electric heaters are a fixture in many offices, workshops, and commercial premises — particularly during winter. They're also one of the most common causes of electrical fires in UK workplaces. The Fire Brigades Union estimates that portable heaters are involved in a disproportionate number of electrical fires relative to their number. Regular PAT testing is essential.
Why Portable Heaters Are Higher Risk
- They operate at high temperatures, which degrades components faster
- They're frequently moved, which can damage cables and connections
- They're often used in conjunction with extension leads not rated for the load
- Dust and debris can accumulate inside, creating a fire hazard
- Older heaters may not have modern safety features such as tip-over protection
Recommended Testing Frequency for Portable Heaters
The IET Code of Practice recommends testing portable heaters in offices every 12 months — more frequently than standard IT equipment. In environments where heaters receive heavier use (workshops, warehouses), testing every 6 months is advisable. Always inspect heaters visually before each winter season at a minimum.
What PAT Testing Checks on Heaters
During PAT testing, heaters are visually inspected for damaged cables, cracked or damaged casings, burn marks, and blocked air vents. Electrical tests check earth continuity (crucial for metal-bodied heaters), insulation resistance, and correct fuse rating. Any heater showing signs of overheating or dust accumulation inside the element will be failed.
Practical Safety Advice for Portable Heaters
- Never place portable heaters next to flammable materials or fabrics
- Plug heaters directly into wall sockets — not extension leads
- Never leave heaters running in unoccupied rooms
- Ensure heaters have modern tip-over cut-off safety features
- Replace any heater more than 10 years old even if it passes PAT testing
