Littleton is an old town with a lot of 1980s and 90s subdivisions, and those houses are well into their water heater replacements.
Littleton water heaters at a glance
| Water provider | Denver Water serves all City of Littleton residents |
|---|---|
| Water hardness | About 105 mg/L on average in 2025 (roughly 6 grains per gallon), ranging from 55 to 124 mg/L. Moderately hard, and a little harder in winter. |
| Homes | Median year built 1982 |
| Elevation | About 5,351 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 2026 water quality report · Census ACS 2019–2023 via Point2Homes · USGS elevation. Checked October 2026.
What Littleton'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. Denver Water serves all of Littleton, and its water averaged about 105 mg/L of hardness in 2025 (about 6 grains per gallon). Moderate scale. A yearly flush and an anode check every few years keep a tank close to its rated life.
1980s and 90s subdivisions
Most Littleton houses went up in the 1980s and 90s, which means most are on their second or third water heater. Denver Water's moderately hard water is easier on a tank than the water farther north, so a well-kept tank can get close to its rated life. Near downtown, the older homes have older piping around the heater, and the shutoff valve is often due too.
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 5,351 feet (Littleton's USGS reference point), a gas water heater has to be rated for the altitude, and a tankless heater set for it at installation. Rinnai and Navien change their tankless settings at 5,400 feet, and elevations vary across the city, so the setting should match your address. 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 Littleton: all plumbing services in Littleton