How long should a tankless water heater last?

  • The standard warranty is 15 years on the heat exchanger and 5 years on the parts. As long as regular maintenance is performed on the tankless water heater and it is installed property (in a residential setting) - you should get 20-30 years of life from the unit. Without regular maintenance, the unit will start to experience significant problems at 7-8 years and may cost more to repair than to replace.