INVESTIGATION

Incident Summary (Reference #5605124)
Incident Date September 22, 2016
Location
Regulated industry sector
Chilliwack
Gas / Propane system
SUPPORTING INFORMATION
Impact
Injury
Damage
Incident rating
Qty injuries 0
Injury
description
Injury rating
Damage
description
Damage rating
Incident overview
None
None
Fire damage to appliance installed outdoors next to fifth wheel trailer. Some charring and
heat damage to the fiberglass exterior of the trailer slide out, trailer exterior and awning.
Appliance total loss.
Minor
Minor
A propane fired on demand water heater was installed in an old refrigerator on the outside of
a fifth wheel trailer. During the operation of the heater a fire started at its installed location.
The fire destroyed the water heater, the refrigerator it was installed in, and damaged the
exterior of the fifth wheel trailer.
Gas appliances installed in British Columbia require a certification mark from a recognised
testing agency. The testing agency reviews the appliance and it’s components as well as the
manufactures installation instructions.
The on demand water heater: Make - Marey
Model – GA10LPDP
INVESTIGATION CONCLUSIONS
Site, system and
components
The on demand water heater is fired by propane gas. Propane regulators on a fixed gas
system lower the pressure of the gas in two separate stages. The first stage lowers the
pressure from tank pressure to 10 psi, and the second stage lowers the gas pressure from 10
psi to approximately 0.5 psi which is the inlet pressure required for most appliances. No
hardwired electricity is required for its operation. When water flow is sensed a battery
powered spark ignitor lights the main burners. The water passes through a series of tubes
around the burners combustion chamber that heat the water for its end use. When the water
flow stops the burners shut off and the unit sits idle until it senses water flow again. The
water heater is designed to be permanently installed indoors. It should be piped into a
permanent propane gas system and the flue exhaust of the unit should travel to the outdoors
using an approved venting system.
Failure scenario(s)
The owner purchased the new uncertified water heater online. The owner installed the water
heater himself in an old upside down RV refrigerator outdoors at the rear left hand corner of
the fifth wheel behind the slide out portion of the trailer. The door of the refrigerator was left
in the open position when the incident occurred.
Propane gas was supplied to the unit from a 20lb propane cylinder using a single stage
propane regulator on the cylinder and a 10 foot long 5/16 inside diameter propane hose. The
hose had a 3/8 female brass flared fitting factory crimped on the end. The hose was
connected to a 3/8” x 1/2” male flare brass fitting. The 1/2“ flared portion of the brass fitting
BRITISH COLUMBIA SAFETY AUTHORITY
www.safetyauthority.ca

Incident Summary (Reference #5605124)
was incorrectly installed into a 1/2” female black iron coupling. The coupling is designed to
accept 1/2 male iron pipe thread which is larger than the 1/2 brass fitting threads.
A tight fitting hole was cut in refrigerator above the heater and a 4 foot long 4” diameter
piece of double wall galvanized B-vent was placed on the flue outlet of the heater unsecured.
The hot water tap was turned on in the trailer for the shower and within a minute or two a
sound was heard and the occupant looked outside and saw smoke and flames coming from
the water heater.
Facts and evidence
Appliance installation instructions
- Unit designed for indoor installation
- Venting should be secured to appliance using a vent connector
Statement from the owner
- He purchased the heater online and installed it himself with help from his neighbor.
The fire incident report from the fire department
- The appliance venting was sticking out of the refrigerator at an approximately 45
degree angle when they arrived.
Photos indicate
- The most amount of wood charring was at the top of the wood frame installed in the
refrigerator indicating fire source location
- The fire pattern on the B-vent indicates the vent was on an angle when the fire was
burning
- The brass fitting on the gas line was incorrectly installed in the black iron coupling
Causes and
contributing factors
It is likely that the unsecured venting for the unit became dislodged allowing the high
temperature flue gasses to ignite the plastic and foam insulation of the refrigerator to. The
resulting fire may have melted the rubber gas hose allowing gas to escape contributing to the
fire damage.
It is also plausible that the incorrect connection of the brass flare gas fitting into the black iron
coupling leaked gas when the propane cylinder was turned. The gathering gas could have
ignited when the hot water to the shower was turned on and the heater lit the main burners
creating a source of ignition..
Photos or diagrams (if necessary)
BRITISH COLUMBIA SAFETY AUTHORITY
www.safetyauthority.ca

On demand water heater installed in old refrigerator outdoors
BRITISH COLUMBIA SAFETY AUTHORITY
www.safetyauthority.ca

Burn Pattern from top down
BRITISH COLUMBIA SAFETY AUTHORITY
www.safetyauthority.ca

Fire pattern angle on B-vent
BRITISH COLUMBIA SAFETY AUTHORITY
www.safetyauthority.ca

Gas hose and fittings
BRITISH COLUMBIA SAFETY AUTHORITY
www.safetyauthority.ca

Incorrect brass fitting ( ½” flare fitting threaded into a ½” iron pipe thread
coupling)
BRITISH COLUMBIA SAFETY AUTHORITY
www.safetyauthority.ca