Heating element failure: If water is lukewarm or not heating at all, the heating element or thermostat may need replacement. Cost varies based on element type and access.
Leaks: Small leaks from connections are cheaper to fix than tank leaks. Tank leaks often require full replacement.
Pressure issues: Low hot water pressure could be due to valve problems or scale buildup inside pipes.
Control faults: Error codes, display issues, or inconsistent temperature control may need circuit board repairs.