Most homeowners expect 10 to 12 years out of a tank water heater. In Mesa and the rest of the East Valley, a lot of them don't make it that long. The reason is the water itself. Hard water works quietly inside the tank, out of sight, until a unit that seemed fine starts popping, leaking, or running out of hot water.
Here's what hard water does to a water heater, how hard the water really is in your city, and what actually slows the damage down.
How Hard Is the Water in Your City?
Water hardness is the amount of dissolved calcium and magnesium in your water, measured in grains per gallon (GPG). Anything above 7 GPG is considered hard. Every East Valley city is above that, but the numbers vary more than most people think. These come from each city's own water quality report:
Mesa: about 12 GPG in the City Zone and about 16 GPG in the Eastern and Southern zones
Gilbert: averages about 10 GPG (range 6 to 13.5)
Chandler: averages about 16.5 GPG (range 5 to 20)
Queen Creek: Town water averages about 12 GPG; EPCOR areas run 15 to 18 GPG
San Tan Valley: EPCOR's San Tan system reports 15 to 18 GPG
Apache Junction and Gold Canyon: no published hardness number, but the groundwater is hard and we see heavy scale on fixtures and water heaters there
Hardness can also change during the year as cities switch between river water and wells, so your water may be harder in summer than in winter.
What Hard Water Does Inside a Water Heater
When hard water is heated, calcium carbonate drops out of the water as a solid. That's the white, crunchy scale you see on faucets and showerheads. Inside a water heater, it causes four problems.
Sediment on the bottom of the tank
Scale settles on the tank bottom, right where a gas burner or the lower electric element heats the water. That layer acts like insulation, so the heater runs longer to reach temperature and your gas or electric bill goes up. In gas units it also creates hot spots that wear out the tank bottom. If your water heater pops, rumbles or crackles while it heats, that's water trapped under the sediment boiling its way through. It means the buildup is already heavy.
Scale on electric heating elements
In electric water heaters, scale coats the elements directly. A coated element runs hotter and burns out sooner, sometimes in just a few years. One element replacement is a reasonable repair. Repeated element failures on an older tank usually mean it's time to look at the bigger picture.
Anode rods used up faster
Every tank has a sacrificial anode rod that corrodes so the tank doesn't. In mineral-heavy water, that rod gets used up faster. Once it's gone, the tank starts rusting from the inside. Rusty hot water, a metallic smell, or water at the base of the tank are signs that corrosion is far along, and at that point replacement is usually the answer.
Scale in valves and connections
Scale also builds up in the supply lines, the connections on top of the tank and the temperature and pressure (T&P) relief valve. That can restrict flow, keep the relief valve from working as it should, and start small leaks at fittings.
How Much Sooner Do Water Heaters Fail Here?
It depends on the unit, how much hot water you use, and whether it's been maintained. As a general rule, a tank that might last 12 to 15 years in a soft-water area often lasts closer to 7 to 10 years in East Valley water, and less if it's never been flushed. If yours is in that range, read our guide to the signs it's time to replace a water heater.
What Actually Protects Your Water Heater
Flush the tank once a year
An annual flush removes sediment before it hardens. In our water it's basic maintenance, not an extra. If a tank has gone years without a flush, the sediment may be too hard to drain out, and a professional service is the better option.
Check the anode rod every 2 to 3 years
If the rod is more than half gone, replace it. Check more often if you have a water softener, because softened water uses up anode rods faster. Most homeowners have never had this done, and it's one of the cheapest ways to add years to a tank.
Keep it at 120°F
Higher temperatures make minerals drop out faster. 120°F is hot enough for most homes, reduces scale, and lowers the risk of scalding.
Consider a water softener
A whole-home softener removes the calcium and magnesium before it reaches your water heater, pipes, dishwasher and fixtures. In cities at the higher end of the list above, like Chandler, San Tan Valley and the eastern parts of Mesa, a softener usually pays for itself in longer equipment life. Learn more about water softeners and water treatment, or see the page for your city: Gilbert, Chandler, Queen Creek, San Tan Valley, Apache Junction or Gold Canyon.
If you have a tankless unit, descale it every year
Tankless water heaters don't have a tank to fill with sediment, but hard water scales up the heat exchanger instead. That leads to error codes, lower flow and eventually an expensive heat exchanger repair. In East Valley water, plan on descaling once a year, or pair the unit with a softener. See our tankless water heater page for more.
Warning Signs Your Water Heater Is Already Damaged
Popping, rumbling or crackling while it heats
Rusty or discolored hot water
A metallic taste or smell from the hot tap
Hot water running out faster or taking longer to recover
Higher gas or electric bills with no change in use
A tank that's 7 or more years old and has never been flushed
Moisture or a small puddle at the base of the tank (call a plumber soon)
Get an Honest Look at Your Water Heater
If you can't remember the last time your water heater was serviced, now is a good time. We'll flush it, check the anode rod, and give you an honest read on how much life it has left, with the price before we start. Learn more about our water heater repair and replacement, or find your city: Gilbert, Chandler, Queen Creek, San Tan Valley, Apache Junction and Gold Canyon.
Call Mountain Vista Plumbing at 480-847-9769 or send us a message.