What a whole house water filter costs
The hardware is the smaller number. A whole house system is bought once and its cartridges are bought every year for as long as you own it, so the sticker decides very little. The figure that compares two systems is cost per thousand gallons of filtered water, which folds the hardware, the cartridges and the capacity the manufacturer rates it for into one number.
Measure our own page that way and two things show up that the sticker hides. Among the systems taking the same cartridges, the WGB22B 2-Stage Whole House Water Filter System makes the cheapest water and the WGB32BM Iron & Manganese Whole House Water Filter System costs 1.7x as much per thousand gallons. And the cheapest hardware on the page, the WCB32O 3-Stage Whole House Water Filter System, is rated for a 3.3 times smaller volume than the rest, so it reaches the end of its rated life that much sooner. A low price on a system you replace three times over is not a low price.
What each system costs to run
Cost per thousand gallons is the hardware plus one year of cartridges, divided by the capacity the manufacturer rates the system for, and then divided through by the best system on the page. So the column below reads as a multiple: 2.0x means twice as much per gallon of filtered water. It is a first-cycle figure, so it flatters nothing, and it is the comparison the sticker price hides.
| System | Stages | Rated for | Cost per 1,000 gal |
|---|---|---|---|
| WGB32B-PB Lead-Reducing Whole House Water Filter System Best for lead | 3-stage | 100,000 gal | Takes different cartridges |
| WGB32B 3-Stage Whole House Water Filter System Best overall | 3-stage | 100,000 gal | 1.5x |
| WGB32BM Iron & Manganese Whole House Water Filter System Best for well water | 3-stage | 100,000 gal | 1.7x |
| WCB32O 3-Stage Whole House Water Filter System Lowest upfront cost | 3-stage | 30,000 gal | Takes different cartridges |
| WGB22B 2-Stage Whole House Water Filter System Best value | 2-stage | 100,000 gal | 1.0x |
Two systems carry no multiple, for two different reasons. One is lead-reducing and takes a lead-specific third cartridge that is not among the four on our replacement page. The other is the WCB32O 3-Stage Whole House Water Filter System, which takes 20 by 2.5 inch cartridges rather than the 20 by 4.5 inch size the rest of the range uses, so the same arithmetic would be pricing a part that does not fit it. A number that fits a different machine is worse than no number, and it is also why the cheapest system here cannot be compared on this column at all: the capacity row is the one that tells you about it.
The cheapest system to buy is not the cheapest to own
The WCB32O 3-Stage Whole House Water Filter System is the lowest upfront price on our whole house page, and it is rated for 30,000 gallons where the systems above it are rated for 100,000. It also takes 20 by 2.5 inch cartridges rather than the 20 by 4.5 inch size the rest of the range uses, which is a smaller cartridge doing the same job.
That is not a reason to avoid it. It is a reason to know what you are buying: a lower price for a system that reaches the end of its rated life roughly three times as often. If the house is small or the water is already good, that may be exactly the right trade. If it is a family on a well, it is the expensive option wearing a cheap price.
Where the running cost actually goes
Three things move the yearly figure more than the choice of brand.
- Sediment load. The sediment cartridge is the cheapest part in the system and the one that needs changing most often. On a well producing sand it can want changing at three months rather than six, which doubles that line and nothing else.
- Whether you buy the set. The three-stage set costs less than the same three cartridges bought separately, so the set is the cheaper route as well as the one that keeps the stages on a single date.
- Iron and manganese. The catalytic cartridge is roughly 3.0 times the cost of the sediment stage, and it is what makes a well-water system cost more to run than a city-water one. It also does nothing useful on municipal water, where those metals have already been dealt with.
What makes it cost more than it should
- Running the sediment stage long. It loads the carbon behind it, so the cheapest cartridge in the system shortens the life of the two most expensive.
- Fitting the cartridges in the wrong order. A carbon block in the first position is ruined by grit before its media is spent. Which cartridge goes where is on the replacement page.
- Filtering the garden. Outside taps teed off after the filter spend cartridge life on water nobody drinks. Tee them off before it, which is a decision made once during installation.
- No bypass. It does not cost money directly, it costs changes. Cartridge swaps that need the whole house shut off get postponed, and an overdue filter is money already spent doing less than it should.
Fitting it
Labour depends on your plumbing rather than on the filter, so a local quote beats any national figure. What moves it: whether the main is copper, galvanised or plastic, whether the existing shut-off valve still closes fully, whether a three-valve bypass is going in at the same time, and whether the run needs soldering. Doing it yourself is realistic if you are confident cutting into the main, and the installation guide covers the decisions that are not in the box.
Common questions
How much does a whole house water filter cost?
A cartridge-based three-stage system is typically a few hundred dollars for the hardware, with a set of cartridges each year on top and fitting on top of that again. Tank-based systems start considerably higher and last up to ten years on the main media. The hardware is the number people compare, and the cartridges are the number that decides what the system actually costs you, because you pay them again every year for as long as you own it.
What is the ongoing cost of a whole house water filter?
A set of cartridges a year for most households, changed every 6 to 12 months, plus a sediment cartridge more often on a well that produces sand. Buying the stages as a set rather than separately is usually cheaper and keeps them on one schedule, which matters because a system whose three cartridges were changed on three different dates is one nobody can keep track of.
Is a cheaper whole house filter worth it?
Not automatically, and the capacity rating is why. The lowest upfront system on our page is rated for 30,000 gallons where the larger ones are rated for 100,000, so it reaches the end of its rated life about 3.3 times as often, and it takes a smaller cartridge to do it. Among the systems that do share cartridges, cost per thousand gallons still spreads from 1.0x to 1.7x, so even like-for-like the sticker price is a poor guide. The cheapest system to buy is not the cheapest to own.
Does a whole house filter save money elsewhere?
It stops sediment collecting in the water heater tank, which is the clearest mechanical benefit, and it means anything downstream is running on filtered water. Treat those as reasons to fit one rather than as savings to count against the cost, because neither is easy to put a figure on for a particular house.
How much does it cost to install?
That depends on your plumbing rather than on the filter, so get a local quote rather than trusting a national figure. What moves the price: whether your main is copper, galvanised or plastic, whether the shut-off valve still closes, whether a three-valve bypass is being added at the same time, and whether the run needs soldering. Fitting it yourself is realistic if you are confident cutting into the main.
Related
- Best whole house water filter systems, the systems in the table above, scored
- Whole house replacement cartridges, and which position each belongs in
- Installing a whole house filter, and what decides the quote
- How we rate, and why price is not one of the four things we score