Systems & CodeQuestion 46 of 110
A water heater is installed in a garage where flammable vapors may be present. What installation requirement addresses ignition of those vapors?
a.Install a drip leg only
b.Elevate the ignition source at least 18 in above the floor, or use an approved flammable-vapor-ignition-resistant unit
c.Provide combustion air from the attic
d.Add a second T and P valve
Explanation
In a garage the pilot or ignition source must be at least 18 in above the floor, because gasoline vapors are heavier than air and pool low, unless the heater is listed as flammable-vapor-ignition-resistant (FVIR). Modern FVIR heaters are designed to prevent flame rollout from igniting floor-level vapors. Combustion air and relief valves do not address vapor ignition.
Law Reference: UPC §507.0Practice all 110 questions free — no signup required.
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