how do you turn down the temp on a water heater?

Depends on the type of water heater you have. The less expensive Electric ones have the thermostats attached to the tanks and under a metal cover as described above. Be sure to set both the top and bottom thermostat to the same temperature.

The NG & Propane water heaters will have a knob near the opening to the fire box. The knob will have numbers on it and you simply turn the knob to increase or decrease the water temperature.

The more expensive Electric, NG & Propane ones will have a thermostat that is mounted on the wall or exterior of the tank and looks like your thermostat for the HVAC system. You set it the same way you set the HVAC thermostat.

The advantage of the more expensive water heaters is you can program the heater to increase or lower the temperature when you need it, such as low during the night, increase just before you get up and bath before going to work. Thus, they use less energy and over time allow you to recoup some of the cost.

1) the answers above are right but...
2)electric water heaters normally have two elements one about half way up and one near the bottom. They should both be at the same temp.
3)minimum (recommended) temp for an electric water heater is 130 degrees.
4)oil water heaters have a adjustment knob on the side easy to see
5)furnace fired water heaters are another matter
Good Luck!

Check out the owner's manual, and it will give you instructions on how to do it. Usually you need to remove a cover plate, and change the settings.
Sometimes they have a know, or switch for you to turn down. Or in some cases, a screw, with an arrow that you set against the temperature setting you want.
120 degrees is usually the best setting.
If your temperature setting is close to the Electrical Connections, and some are, be sure to turn off the power, if you have to use a screwdriver.
It should only take you a few minutes to do the job, once you know where the controls is located.

Turn Down Water Heater

For the best answers, search on this site https://shorturl.im/axVP7

I don't believe there are any rules in California that specifies the temperature of hot water in an apartment. I presume the landlord pays for the hot water and he wants to keep his expenses low. I would not research the law too closely, because I think it's a waste of time. Let's say you actually find a law that says the temperature has to be 180 degrees (and there isn't). You tell the landlord and he raises the temperature. Then next month he gives you a 60 or 90 day notice to vacate the premises, which he can do for any reason or no reason at all. So you win the battle, but lose the war. My suggestion is to bring the landlord to your apartment when the hot water is actually cold and let him feel it with his hands. Keep in mind that his opinion of cold may be vastly different than yours. Then offer to pay an extra $10/month for the agreement to keep the temperature at about 170 degrees. You also have to remember that it is the gas company which recommends to keep the water heater at its lowest setting of about 120 degrees. So the landlord just follows the utility company's advise to save energy.

by the aqua stat

see link below for information on adjusting the temperature

go to the heater near the bottom of the tank there are your controls will read warm, hot,etc. turn towards cooler ie water tanks should not go above 140 temp wise should always check temp at faucet with a good thermometer it will take a while to cool down unless you want to waste water this is for a gas heater guy above is right for elec