Hazard alerts (2014)

Oil filled column heaters

In colder months, some areas may consider portable heaters to supplement workplace heating. This hazard alert relates to an incident last winter regarding oil-filled column heaters in the workplace.

An oil-filled column heater overheated uncontrollably, causing one of the column seams to split under excessive pressure, releasing the superheated oil. Visible orange flames approximately 30 cm above the height of the upper column joints were observed and the room quickly filled with black sooty smoke and an unpleasant odour. The heater was immediately turned off, unplugged and allowed to cool. The heater at the time was partially under an office desk.

Subsequent investigations revealed that the heater's thermal safety fuse (designed to cut off if the unit's temperature reaches 130°C) had failed to activate, causing it to overheat excessively.

The heater showed no obvious signs of damage. What isn't known is whether the heater suffered any damage that would weaken the fin seals.

To prevent similar incidents:

• Portable heaters (e.g. oil column heaters, fan heaters) should only be considered where there is no building heating (e.g. radiant wall heaters, vented systems, reverse cycle air-conditioning). The use of additional heaters can upset the thermal sensors and thereby the comfort of other occupants.
• The use of portable heaters should be approved by local area management. The use of privately owned electrical heating appliances is to be discouraged.
• All portable heaters must be regularly inspected, tested and tagged as part of the University's In-service safety inspection and testing of electrical equipment process. Note: Confirmation of the reliability of the safety tilt switch is recommended as one of the tests for this style heater.
• See the Electrical Safety Management Procedure.
• All heaters must have ample space around and above it. Keep away from walls. Do not place anything on top or allow anyone to sit on the heater. Keep away from combustibles including paper and recycling bins, desks, and curtains to minimise the risk of fire.

If you require under desk heating, electric panel heaters are an appropriate solution.