Tankless Water Heater in Riverside, CA

How tankless compares

The U.S. Department of Energy reports that for homes using 41 gallons or less of hot water a day, demand heaters can be 24% to 34% more energy efficient than storage tanks. Gas models generally deliver higher flow rates than electric ones.

Hard water and descaling

RPU's water quality report lists average hardness of 197 mg/L. In a tankless heater, minerals collect inside a small heat exchanger instead of settling in a tank, and scale there can trigger error codes, reduce flow and shorten the unit's life. Most manufacturers call for periodic flushing with a descaling solution through the service valves. A water softener or scale-reduction filter upstream can reduce how often that is needed.

Common service calls

• Error codes tied to scale, ignition or venting
• Water that swings between hot and cold during a shower
• No hot water at low flow, such as a single faucet barely open
• Missing isolation valves, which make flushing difficult

Switching from a tank

Gas tankless units usually need a larger gas line and new venting, and electric models can need a significant electrical upgrade. A permit from City of Riverside Building & Safety covers the plumbing side. Ask the plumber to check your gas meter and line sizing before committing.

Sizing a tankless unit

Tankless heaters are sized by flow rate and temperature rise, not gallons stored. Add up the fixtures that might run together, such as two showers and a dishwasher, and compare that demand with the unit's rating. A plumber will check the incoming water temperature and pick a model with enough capacity for the rise you need. Some larger homes use two units or a small buffer tank to cover peak use.

Cost factors

• Gas or electric, and the unit's flow capacity
• Gas line, venting and electrical changes
• Whether isolation valves and a softener or filter are added
• Mounting location, indoors or on an exterior wall