Navien WEC600
Installed

Often yes — but it has to be checked, not assumed. The WEC600 handles feedwater up to 350 ppm hardness (about 20.5 grains) and 500 ppm TDS. Typical Prescott city water runs around 15 grains, comfortably inside that. A good number of area wells fit as well — a recent Prescott install tested at 20 grains and came in under the limit, though with only 8 ppm to spare, and well hardness moves with the season. Past roughly 20 grains you are outside the unit’s range and a conventional softener is the right answer. That is why it starts with a free on-site water check — hardness and TDS measured at your house before you spend anything. Anyone quoting a WEC without testing first is guessing with your money.

A conventional softener uses ion exchange and salt, and needs a brine tank and periodic salt refills. The WEC uses electro-membrane capacitive deionization — an electrical process that pulls hardness minerals and total dissolved solids out of the water — so there is no salt, no brine tank, and nothing to haul. It is tankless and wall-mounted, roughly an appliance footprint rather than two tanks in the garage. It also reduces TDS, which a softener does not do at all: a softener swaps calcium and magnesium for sodium and leaves total dissolved solids essentially unchanged.

Three things at the point of entry: water in and out, a 120V electrical outlet, and a drain connection. The drain matters because the system recovers up to 85% of the water and sends the rest, plus periodic Clean-In-Place cycles, down the drain. It must be installed indoors, on a flat surface, out of the weather, by a qualified installer. If your existing softener loop already has power and a drain nearby, the install is straightforward. If power or drain has to be run, that is quoted separately and approved before work starts.

Far less handling than salt, but it is not maintenance-free. Filters and a Clean-In-Place cycle come due roughly every 50,000 gallons or six months for a typical family of four. The system runs the CIP cycle automatically, but it uses a citric acid solution that is consumable and sold separately — budget for it the way you would budget for salt, just less often and without the lifting. The 10-micron sediment pre-filter and 1-micron carbon block post-filter are replaceable on the same general schedule.

It depends what you are actually buying. If never handling a salt bag again, reclaiming the garage space, cutting TDS as well as hardness, and app connectivity are worth a real premium to you, then yes. If your goal is simply to stop scale at the lowest cost, a conventional softener does that for substantially less money. Both are legitimate choices. What is not legitimate is selling you a WEC for water it cannot treat, which is why the test comes first.

The WEC is NSF/ANSI certified, NSF 42 certified for chlorine and odor reduction, and certified by IAPMO to Z601 for 94% scale reduction. It won a Red Dot Design Award in 2023 and was an IDEA Awards featured finalist in 2024. Navien's warranty is 1 year labor and 3 years parts, extending to 5 years parts when the unit is registered — registration is free and doubles your parts coverage, so it is handled during the install rather than left to you.

Aqua Cat installs Navien WEC600 systems across Prescott, Prescott Valley, Chino Valley, Dewey-Humboldt, Sedona and Cottonwood. Every WEC quote starts with a certified lab water test to confirm hardness and TDS fall inside the unit's limits, because installing one outside spec means it will not perform. If your water is too hard for the WEC, you will be told that and pointed at a conventional softener instead.