Centennial's homes are mostly from the 1970s and 80s, and its water comes from several districts instead of one city utility.
Centennial water heaters at a glance
| Water provider | No city utility. Several districts serve Centennial, many of them delivering Denver Water's water (Southgate, Castlewood, Havana, Southeast Englewood, Willows). East Cherry Creek Valley serves the eastern part of the city. |
|---|---|
| Water hardness | Denver Water–supplied districts averaged about 105 mg/L in 2025. East Cherry Creek Valley doesn't publish a figure. |
| Homes | Median year built 1983, and about half the homes went up in the 1970s and 80s |
| Elevation | About 5,837 feet (USGS reference point) |
| For your water heater | Moderate scale. A yearly flush and an anode check every few years keep a tank close to its rated life. |
Sources: Denver Water distributors · Denver Water 2026 water quality report · Census ACS 2019–2023 via Point2Homes · USGS elevation. Checked October 2026.
What Centennial's water does to a water heater
When water is heated, the calcium and magnesium in it drop out as sediment and settle on the bottom of the tank. The burner or lower element then has to heat through that layer, so the heater runs longer, pops and rumbles, and wears faster. Most Centennial districts deliver Denver Water's water, which averaged about 105 mg/L of hardness in 2025; East Cherry Creek Valley, in the east, doesn't publish a figure. Moderate scale. A yearly flush and an anode check every few years keep a tank close to its rated life.
Southglenn, Willow Creek, Piney Creek
In neighborhoods like Southglenn, Willow Creek, and Piney Creek, the original water heaters are long gone, and many houses are on their third. Most of these heaters live in a basement or a garage, and a replacement is the time to swap a stiff shutoff valve and add a drain pan if the heater sits over a finished floor. Where your water comes from depends on your district; your water bill names it.
Repair or replace?
Under about eight years old, with a failed part like a thermocouple, gas valve, heating element, or thermostat, a repair usually makes sense. At about ten years or older, or with any leak from the tank itself, replacement is the better money: a leaking tank can't be fixed. You get the price before any work starts, and most replacements are done the same day they're quoted, with the old unit hauled away. A replacement is also the time to check whether you need an expansion tank (when one is required).
Gas or electric, tank or tankless
We repair and replace both gas and electric water heaters, standard tanks and tankless units. Tankless works well at this hardness. Descale it about once a year so scale doesn't choke the heat exchanger.
At about 5,837 feet (Centennial's USGS reference point), a gas water heater has to be rated for the altitude, and a tankless heater set for it at installation. That's above 5,400 feet, where Rinnai and Navien change their tankless settings, though elevations vary across the city. What to check at altitude.
Make the next one last
- Flush the tank once a year to clear sediment
- Check the anode rod every few years
- Descale a tankless unit about once a year
- Know where the cold-water shutoff on top of the heater is, and how to turn the heater off, before you need to
More reading: water heater leaking? what to do, no hot water troubleshooting, how long water heaters last in Colorado, why a water heater pops or rumbles, and water hardness by city. If your water is hard, a softener protects the heater and every fixture.
Recent water heater work
Photos from our own jobs. Locations and customer details are left out.
More in Centennial: backflow testing in Centennial · all plumbing services in Centennial