Start with the symptom
No hot water, inconsistent temperature, visible leakage, unusual noise and pilot or ignition problems do not all point to the same repair.
Replacement becomes more likely when
- The tank itself is leaking or badly corroded
- Multiple age-related components are failing
- Venting or installation conditions need major correction
- The unit is near the end of its practical service life and repair cost is climbing
Send useful information
Photos of the full unit, data label, water connections, venting and the area around the heater help identify what type of replacement scope may be involved. Gas and electrical work should be handled with the appropriate safety and trade requirements.