There was some fire/heat damage sustained by the gas appliance and the commercial kitchen sustained minor smoke damage.
Damage rating
Insignificant
Incident rating
DESCRIPTION
Incident overview
Site, system and components
CONCLUSIONS
Failure scenario(s)
Facts and Evidence
Insignificant During the night a propane fire started underneath a commercial range located within a commercial kitchen. The fire stayed isolated to the commercial range but burned through the night creating large amounts of smoke. When discovered the next morning the staff isolated the propane supply to the kitchen and extinguished the fire. The appliance involved is a commercial range which is comprised of six open propane fired stove top burners above and a propane fired oven below which is temperature controlled by a thermostat located within the oven. The oven burner is designed to allow gas to flow into the burner (through the orifice) when there is a call for heat, the flow of gas then draws air in through the primary air shutter to mix with the gas, this gas and air mixture is then designed to be ignited by the pilot light once it exits through the burner ports within the ovens burner compartment. The oven portion of the range was accidently left on at the end of the day and was allowed to run all night. At some point throughout the night the oven turned on to heat up and rather than the propane gas burning through the burner ports as intended, the propane gas began to spill out and burn through the primary air shutter. Due to the fact this flame was no longer burning within the oven`s burner compartment it would not have effectively heated up the oven to turn the burners off, this would have allowed the oven to run for an extended period of time. The resulting large dirty and impinged flame filled the commercial kitchen with a large amount of smoke which would have additionally contained highly elevated levels of carbon monoxide. Since there were no smoke alarms or carbon monoxide detectors in the kitchen and the flame was not large enough to set off the sprinkler heads the condition went unnoticed until staff arrived in the morning to open the kitchen. 1. The management of the establishment stated that they had not had a routine maintenance plan in place and had only been bringing in contractors to repair issues as they presented themselves. 2. The appliance manufacturer requires that the oven burners be removed and cleaned periodically as part of the routine maintenance plan.“Remove burner and clean with warm water and wire brush. Make sure the tiny burner ports are not clogged.”
BRITISH COLUMBIA SAFETY AUTHORITY
www.safetyauthority.ca
Incident Summary (Reference # 5575833) 3. The oven burner ports are blocked from significant amounts of soot. (see photograph #3). 4. The soot/burn pattern around the primary air shutter and up the front door of the oven suggests that propane gas was allowed to escape and burn through the primary air opening for a period of time (see photograph #4). 5. The isolated damage to the oven suggests that the origin of the fire and smoke was directly from this location of the appliance. 6. When the oven was tested (burner turned on) gas immediately escaped and ignited through the primary air shutter (see photograph #5).
Causes and Contributing Factors
The main cause of the improper operation of the oven burner can likely be attributed to a lack of thorough maintenance by a licensed gas contractor. An additional contributing factor to the incident was human error as this piece of equipment had been accidently left on overnight on the evening of the incident.
Photos or diagrams (if necessary)
Range
BRITISH COLUMBIA SAFETY AUTHORITY
www.safetyauthority.ca
Rating Plate
BRITISH COLUMBIA SAFETY AUTHORITY
www.safetyauthority.ca
Oven Burner (see soot blocked burner ports)
BRITISH COLUMBIA SAFETY AUTHORITY
www.safetyauthority.ca
Primary Air Shutter / Pilot Safety Valve (see sooting/burn pattern)
BRITISH COLUMBIA SAFETY AUTHORITY
www.safetyauthority.ca
Flame in Operation (combustion behind burner outside of oven compartment)
