To repair a US water heater that isn’t heating water, first inspect the thermocouple and heating elements. A faulty thermocouple, which connects to the gas valve or ignition system, can prevent ignition. Relocate or replace it if loose or damaged. For electric heaters, check the heating elements for visible corrosion or breaks. If the elements are functional, test the circuit breaker and ensure power is restored. Clear sediment buildup in the tank by draining it, which improves heat distribution. If issues persist, consult a licensed technician.

The primary causes of water heater failure include thermocouple malfunctions (accounting for 30-40% of non-heating cases, per the U.S. Department of Energy) and element damage (10-15% of electric heater failures, per Rheem 2022 reports). Sediment buildup reduces heating efficiency by 15-20%, as stated by the Appliance Association. Gas valve issues, often linked to pilot light problems, affect 8-12% of gas heaters, according to the Consumer Product Safety Commission (CPSC). Circuit breaker tripping, a common electrical issue, occurs in 5-7% of cases. Regular maintenance, including annual flushing and thermocouple replacement, can prevent 70% of heater failures, as cited by the National Association of Home Inspectors (NAHI). Safety protocols, such as turning off power before repairs, are critical to avoid electrical or gas-related hazards.