Water heaters are probably the appliances we most take for granted. They sit in the attic, basement, or closet, never to be looked at or touched unless something goes wrong. Maybe the pilot won’t light because of a bad thermocouple, maybe the heating elements are burnt out, or maybe the unit has just exceeded its lifespan. Whether or not the water heater can be repaired or needs to be replaced really depends on what is specifically wrong with your unit.
No Hot Water - A lack of hot water in your home can be caused by dozens of things, many of which have nothing to do with the water heater at all
(e.g. broken supply line, bad shower cartridge, etc). That being said, there are a few standard causes to look for in the event that your water is chilly.
For electric units, the heating elements are the most common cause. Usually, they just need to be replaced after years of use. Heater thermostats also have
a tendency to go out. For gas units, the pilot assembly, thermocouple, or gas supply may be the culprit. For both gas and electric units, it’s possible the
valve on the outgoing hot water line is stuck shut (though that isn’t the most common issue you’ll find with units).
Unit Leaking Water - A leaking water heater can indicate any of several problems, ranging from loose valves to a corroded water tank.
If the unit is leaking, then that could be a problem with the relief valve, a bad fitting, a clogged drain line in
the overflow pan, or that your tank has rusted all the way through. Most of those are pretty simple issues to fix, but if excessive rust is the problem, then
it will have to be replaced immediately.
Unit Making Noise - If your water heater is making strange “popping” noises, then chances are your unit is on its last leg. These noises
are a sign that sediment has collected inside of the tank, resulting in excessive heat and deterioration of the unit. If you hear this noise in your home, then make sure you start planning for your water heater replacement now.