Can a water heater be installed directly on the floor?
Also asked, can you put a water heater on the floor?
Yes, Gas water heater can not be installed on the floor/ground. Gas water heaters on the ground are possible to explode due to the pilot flame being so close to the floor. Water heaters should not be placed directly on the “dirt,” but they can (absolutely) be installed at floor level with no danger of “exploding.”
Furthermore, should a water heater be off of the floor?
The Uniform Plumbing Code, which establishes standards nationwide, says that the flame or sparking mechanism in a gas water heater must be at least 18 inches off the ground. This means that an accurate measurement for proper installation is not based on the distance from the bottom of the water heater to the floor.
Water heaters only need to be raised (per code) if they are using an ignitable fuel source (gas, propane, etc). And even then, the code is that the ignition mechanism is what needs to be raised. If your water heater is electric or a heat pump, no need to raise it per code.