To present a slide show I downloaded the Chrome browser. to show the browser screen on the Chromecast receiver monitor/TV. For the slideshow I added the Chrome browser iSlide extension. I found that I could not use it directly to present a folder of photos on the laptop.
Gas-fired water heaters require a mechanical permit and electrical water heaters need a plumbing permit to ensure that the unit is installed properly with a temperature and pressure relief valve, the valve has an attached drainpipe, and the entire system is installed in a safe location.
The pilot light from your water heater is the flame that will ignite the fumes from any spilled flammable liquids. If your water heater is NOT a flammable vapor ignition resistance water heater, it must be raised to 18 inches if it is located in the garage where a car would be parked. In some of the cities on the Peninsula and in the Bay Area, you may install a flammable vapor ignition resistance water heater on the ground in a garage.