Rheem's 40 gallon tall natural gas tank with a manufacturer's warranty of 12 years on the tank and it's parts and three years on the repair cost of service labor can be expected to last 12-14 years. Water Heaters Plus! provides a 3 year installation warranty on residential Rheem tanks. If any of the connections we installed leak. We repair it at no additional charge for 3 years. If your water heater leaks in the first 3 years. We will provide the labor for exchange at no cost to you. Permits, if required and any fees charged by the manufacture may be additional. We provide all of this at no additional cost to you.