Signs of Water Heater Failure - Day & Night Air Conditioning, Furnace, & Plumbing

Most people don’t know when their water heater is about to fail. But you can avoid the disruption and damage of a water heater failure by watching for several signs. Here are four indicators that your unit may be on its last legs:

Older Water Heater

In general, water heaters are only made to last 8-10 years. If you don’t know how old your unit is, you can find the age by looking for the serial number on the manufacturer’s sticker on the upper portion of the tank.

The serial number contains the manufacturer date, written as a date code such as “F051052638”.

The letter is for the month – F is the sixth letter of the alphabet, so it represents the sixth month, June. Next, the first two digits of the serial number are 05, representing the year, 2005. So this water heater was made in June 2005. Each manufacturer has a similar date code, but they can vary, so check the manufacturer’s website to learn more.

Rusty Water

If you find rusty water coming from your water heater, this can be a sign that your unit is rusting away on the inside. To avoid replacing a functioning unit, be sure to check that it is actually the tank and not the piping, that is rusting.

Noisy Water Heater

As a water heater ages, sediment will build up and harden on the bottom of the tank. When this happens, you can often hear rumbling or banging sounds coming from the tank. This could be a sign that the unit is at the end of its useful life.

If you start to hear rumbling from your water heater, keep an eye out for any small leaks. If you find one, then it may be time to replace your water heater.


If you notice moisture around your water heater, you may have a small leak or a fracture in the tank. As the metal heats, it expands and if there are slight fractures, water may leak from the tank. Once the metal has cooled the inner tank will stop leaking. Before replacing your unit, make sure there are no other leaks coming from either the fittings or connections to the tank.

If you are concerned about water heater failure or if you discover any of the signs above, contact Day & Night today!