Whole House Carbon Filters

Whole-house buyer's guide

Who whole-house treatment is for

A whole-house system, also called point-of-entry treatment, sits on the main water line. Everything downstream gets the same treated water: showers, laundry, the water heater, the dishwasher and every faucet. A point-of-use system, like an under-sink filter, treats the water at one tap.

Whole-house treatment earns its place when the problem shows up all over the house: a chlorine or chloramine smell in the shower, scale on fixtures and inside the water heater, or a well whose iron stains the sinks or whose sulfur smells like rotten eggs. If your only concern is the water you drink, an under-sink system may be all you need. Our guide to whole-home vs. under-sink walks through that decision.

The whole-home systems we carry

Current prices are on each product page and in the cards above.

What a whole-house system does, and what it doesn't

On city water, the Sentry H2O Whole Home is a whole house carbon filter built around catalytic carbon. It targets chlorine and chloramine, sediment and select heavy metals, and it handles scale with salt-free scale conditioning instead of softening, so the hardness minerals stay in the water. The media type matters if your city disinfects with chloramine, which standard carbon handles poorly; that's the reason for catalytic carbon. We explain the chemistry in chlorine vs. chloramine and what catalytic carbon filtration is.

What it doesn't do matters just as much. A whole-house filter is not a disinfection step; UV is a separate add-on, and its exact supplied model and certificate coverage are still being confirmed with the manufacturer. It isn't a water softener. Both Sentry H2O whole-home filtration systems include an under-sink drinking system. If you're weighing a whole-house system against reverse osmosis, remember that RO usually treats one faucet and sends reject water down the drain; our Sentry H2O vs. reverse osmosis comparison sets them side by side.

Sizing and flow

Start with three numbers: your main line size, your water pressure and the number of people in the house. The city system connects with a stainless SharkBite fitting for a 3/4 inch or 1 inch main line, and NPT threads are available on request. The manufacturer lists an operating pressure of 40 to 80 PSI, with 50 to 70 PSI recommended and 100 PSI as the maximum, and a maximum flow of 9 gallons per minute per tank. A pressure gauge on an outdoor hose bib will show you where your home sits.

If you add UV, size it to the house. The 9 GPM VIQUA VH200 option is sized for one system serving about 1 to 4 people, and the 18 GPM VH410 option runs two systems in parallel for very large homes with 5 or more people. On a well, Sentry H2O sizes the equipment from your lab results.

Installation and plumbing

Plan on a plumber. A whole-home system goes in on the main water line, and the manufacturer calls for professional installation in line with local plumbing code, indoors and protected from freezing and direct sunlight. The city system needs no salt, no brine tank and no drain line, and its single tank fits most utility rooms and garages. The manufacturer also asks you to review compatibility if your water is already salt-softened, and to check pressure, temperature, connections and service clearance before installation. Install costs vary by home, so get your plumber's quote before you order.

Filter life and replacement

The city tank isn't a cartridge you swap. Its media is refreshed with the Whole Home Revitalizer every three years for one person, every two years for two or three people and every year for four or more, and three Revitalizer kits ship with the system. The kitchen under-sink filters are replaced at 3,000 gallons or 1 year, whichever comes first, and a VIQUA UV lamp is replaced every year. On a well, the tank schedule is confirmed with your final configuration. Our guide on when and why to replace your water filter covers building a schedule you'll keep.

City water vs. well water: what changes

City water arrives already disinfected with chlorine or chloramine, so the usual whole-house complaints are disinfectant taste and smell, plus the scale that hard water leaves behind; see hard water and scale: what it costs your home. A private well has no utility treating it. What's in it depends on the geology and land use around it, so iron, manganese, a sulfur smell, nitrates or arsenic can show up in one well and not the next. That's why the well system starts with a lab test instead of a menu, and why our well water 101 guide is the place to start on a well.

The test evidence we publish

Sentry H2O publishes independent lab reports, and our Science page shows the numbers, the weakest one included. In the 2024 Tempe, Arizona PFAS report, PFOA in the sample provisionally mapped to the whole-house system came out 47.47% lower than in the untreated sample. That is a real reduction, and it is well short of the under-sink results on the same page. Every result applies to the sampled water and configuration, is not a certification, and is not tied to a current product number.