The water temperature in the water heater in your house can be adjusted using a device called the aquastat. However, before you start making any adjustments to try to find the ideal temperature—either to save energy or for comfort—we must caution you about what can happen if the water heater is set too low or too high:
- Too low: Both we and the EPA recommend you never set the aquastat lower than 120°F. The water must be hot enough to kill off bacteria and other disease-causing microbes that may develop in the tank.
- Too high: You create a risk of scalding temperatures in the house. We don’t recommend a setting any higher than 140°F.
Q: What type of water heater should I get to have the best money savings?
When people ask our experts this question—and it’s a question we hear often—what they usually want to know is if they should have their current aging 
When the fall starts, HVAC companies remind their customers that it’s time to have maintenance done for their heating equipment. Even Southern California can get the winter blues! But plumbers also ask their customers to arrange for maintenance as well, and it’s for a heating system that Californians need every day, no matter the weather: the water heater.
We’re big proponents of 
As professional plumbers who work on everything from small leaks in homes to large scale commercial plumbing installations, we’re used to encountering one of the biggest enemies of all plumbing systems: corrosion. Corrosion is a chemical reaction between water and metal in the presence of oxygen, resulting in a weakening of the metal. There are different types of corrosion, but rust is the most familiar. No matter the type, corrosion is straight up bad news for metal because it eats into it and eventually causes it to flake away. (In fact, the word corrosion comes from the Latin word meaning “to gnaw.” Corrosion gnaws away at metal.)
The standard water heater that most people think of is a tank water heater, also known as a storage water heater, which keeps a supply of water in a large tank. The water is maintained at a high temperature so that it’s ready for use when a tap turns on somewhere in the building. There are other models of water heater available, such as the tankless water heater, which has become popular in the U.S. over the last decade. A tankless water heater heats up water as it is needed rather than storing it.
