Boiler Maintenance, Decision Making, and Communication: Factors in Shopping Mall Explosion

Location: Burnaby

Regulated industry sector: Boilers, PV & refrigeration - Boiler and pressure vessel system

Incident overview

A mechanical room in a shopping mall sustained damage to the walls and minor fire damage after a gas explosion. Investigation found that a heat exchanger allowed natural gas to backdraft and accumulate in the mechanical room. The high exhaust back pressure safety switch was corroded, and debris was plugging the sensor inlet rendering it ineffective. However, this item was not a part of the manufacturer’s recommended maintenance routine. Additionally, although high levels of carbon monoxide (CO) were found, the boiler still remained in operation. The lack of communication and education of the dangers of continued operation likely contributed to the incident.