The type of water heater you have will determine which ... Once you're done with the smell test, you can turn the gas valve back on. Set the thermostat to your desired setting.

Should you set your thermostat to ’emergency heat’ when weather is very cold? A DOE spokesperson tells Nexstar that data shows nearly 70% of shipments of tankless gas water heaters today ...

For gas water heaters, look for the temperature dial ... Electric water heaters usually have two thermostats -- one at the top and one at the bottom of the tank -- hidden behind access panels.