Saratoga Springs water averages 8.3 gpg (142 mg/L), according to the city’s Culinary Water page. That sits in an awkward middle: above what Takagi, A.O. Smith and Bosch accept, below what Navien, Noritz, Rinnai and Rheem accept. So the brand on your wall decides whether you need treatment, while a yearly flush makes sense for nearly everyone.
Which brands Saratoga Springs water is hard for
The city calls its water moderately hard. The U.S. Geological Survey classes water at 121–180 mg/L as hard, so on the USGS scale the city’s average counts as hard. Either way, here’s how it compares with each brand’s own number:
| Brand | Published hardness limit | Saratoga Springs average |
|---|---|---|
| Takagi | 7 gpg | Over |
| A.O. Smith | 7 gpg | Over |
| Bosch | 100 ppm | Over |
| Navien | 12 gpg | Under |
| Noritz | 12 gpg | Under |
| Rinnai | 200 ppm | Under |
| Rheem | 200 ppm | Under |
“Under” doesn’t mean scale-free. Navien’s manual still recommends once a year (twice a year for very hard water in commercial use) for moderately hard to very hard water with no treatment device. And Takagi’s warranty language is blunt: hard water above 7 gpg (120 ppm) is excluded. If you own a Takagi here and have no softener, that clause applies to you.
Signs your heater is already scaling
Most modern units warn you before scale does real damage. Learn your brand’s code:
- Rinnai: LC on RE Series units means there is scale build-up in the heat exchanger and it needs to be flushed to prevent damage. SENSEI models show SS instead.
- Navien: E760 is a flushing/service alarm (time for routine service).
- Noritz: C1# is a service reminder for periodic maintenance, such as flushing scale from the heat exchanger.
- Rheem: 1L means lime build-up has been detected in the heat exchanger.
Lukewarm bursts, longer waits for hot water and a heater that rumbles or clicks are the other common clues.
Wells, district water and five pressure zones
The city’s 2024 Annual Drinking Water Quality Report lists four city wells plus CUWCD surface water, the wells being numbers 2, 3, 4 and 6. In other words, the supply is Saratoga Springs city wells plus Central Utah Water Conservancy District surface water. CUWCD, the Central Utah Water Conservancy District, says the Central Water Project wells that serve this part of the county are about 1,500 feet deep.
The district’s own numbers don’t match the city’s. CUWCD’s 2021 report put the average hardness of its Central Water Project groundwater at 4.3 gpg, well under the Saratoga Springs average. That’s a wholesale figure from a different year, not a reading from any Saratoga Springs tap, but it shows the parts of the city’s blend aren’t the same.
The same report lists total dissolved solids (TDS) from 144–672 mg/L. TDS isn’t hardness: it counts every dissolved mineral, including ones that don’t form scale. But a spread that wide says the sources aren’t alike.
That matters because of how the system is built. Saratoga Springs is divided into 5 pressure zones, and each zone has its own water tank. The city publishes a single hardness average, not one per zone, so your tap could run a little softer or harder than the headline figure. If you own one of the stricter brands, a test strip is a cheap check before deciding on a softener.
The zones are about elevation and pressure, which matter to a tankless heater in their own way. A heater needs enough flow to fire, and a clogged inlet filter cuts that flow. Rheem, for example, uses code P1 for there is not enough water flow to operate the unit. Cleaning that filter is part of the flush procedure in the Navien and Rinnai manuals, and a technician will usually check it at the same visit.
Services in Saratoga Springs
- Flush and descale for the yearly scale removal most heaters on this water need.
- Annual maintenance, which adds the inlet filter, venting and condensate checks to the flush.
- Repair for low flow, no hot water or a scale code that came back after a flush.
- Installation if you’re choosing a brand: on this water, the limits in the table above are worth weighing.
- Scale prevention for Takagi, A.O. Smith and Bosch owners who are already over their limit.
HomeAdvisor’s range for a tankless flush is $150–$250, and the technician quotes the actual job.
Eagle Mountain
Eagle Mountain, to the west, draws on Eagle Mountain City wells plus Central Utah Water Conservancy District surface water. Its 2025 Annual Drinking Water Quality Report lists five groundwater wells on the groundwater side. CUWCD’s 2021 report names the cities its Central Water Project supplies as Saratoga Springs, Eagle Mountain, Lehi and Vineyard, so the two cities share part of the same district supply.
Eagle Mountain’s report doesn’t publish a hardness figure. What it does publish is total dissolved solids of 148–1,320 mg/L. TDS isn’t hardness, but a spread that large means Eagle Mountain’s sources differ sharply from one another, and a neighbor’s experience may not match yours.
For an Eagle Mountain tankless owner, the practical step is the same as anywhere without a published number: test the cold water at your tap, compare it with your heater’s manual, and flush at least once a year until you know more. Requests from Eagle Mountain go through this page.