Perhaps it should be an axiom of water heater performance–that the older it is, the longer it will last. Water heaters from the 60’s and 70’s or even the 80’s could last 20 years. Not always of course. Today’s conventional water heaters are designed to last 8-12 years. I see them failing before 6 years all the time.
Water heaters may come with warrantees–5 or 10 years. It is usually the same water heater but you pay more for the 10 year warrantee.
This Ruud water heater is still working! It was probably manufactured in about 1931, the year the house was built.
Edwin Ruud designed and patented this gas powered unit around 1900 while working for George Westinghouse (of course) at the Fuel and Gas Manufacturing Company in Pittsburgh. The design is for an instantaneous water heater that uses a system of coils, rather than a tank, to heat the water as it passes through the water heater.
It really should be replaced since it does not have the safety features that modern water heaters have. Primarily the pressure/temperature release valve, which eliminates the possibility of the water heater becoming a rather large bomb.
But it sure says something for the quality of construction from another era. I peeked on ebay and I saw similar Ruud’s selling from $250-750, which would be nearly enough to pay for the replacement. Hmmm.