These used to be called “Culligans”, named after the company that serviced them. They are a simple water filter that is far cheaper to use that the newer “cartridge” style filter systems.
A typical filter costs $25 and lasts 6 months or so. Filters measure 10 inches. The canister that holds the filter is called the housing, and they are a universal, commodity product. I have bought them from Sears and Ace Hardware, but they’re also made by GE, Culligan, Watts, Brita, iFilters, EcoPure, Glacier Bay (a Home Depot brand), Whirlpool, Pentek, and AO Smith.
The standard filter system typically connects to water through 1/4″ plastic tubing. The water is tapped from the supply, somehow. Here’s a brief list of brands and models. Some of the products appear to have been OEMed from the same factory.
Glacier Bay HDGUSS4
AO Smith AO-MF-B
Most of these filter products are kits, and come with the hardware to tap into the water supply. A couple, the Watts and Pentek, do not come with kits, at all (and also need extra parts).
To Kit or Not to Kit
I think if it’s the first time you do this, use a kit. If you’re fixing your system, replace what you need with individual parts.
Make no mistake – the parts in kits are worse. They will break. The faucet will leak and break. The plastic taps will break. The cheap plastic hose will probably break. Even my Sears Kenmore housing sprung a leak after 20 years.
Individual parts cost more, especially for the parts that connect from tube to tube. The problem is learning all the terminology to find the parts, to buy them, so I’ll try to get the names right in this documet.
Once you are buying individual parts, though, each part is pretty cheap. I replaced the Kenmore housing with a Watts housing, and it cost $25 total, $15 for the housing, and $10 for two 1/2″ NPT to 1/4″ push-on connectors.
Bursting Plastic Hose?
I’ve experienced this one time. It was at my parents’, where the fridge was hooked up with some plastic tube. I replaced it with copper tube, and that lasted, I think, 15 years, until the fridge was replaced.
Around 2000, I installed a new water filter system. The old system, which was a restaurant grade, cartridge system, had sprung a leak. It was probably a worn o-ring. Whatever the case, a new head was expensive, and a new filter cost even more. I replaced it with a Kenmore unit from Sears. I think it cost around $60.
I redid the tubing underneath the sink. I kept the tap and replaced the existing vinyl tube (figuring it might also burst). Some was half-inch so I needed to get unions that would bring it down to 1/4″.
The second fridge went in, and the tubing was removed.
Then, later, this second fridge, which was small, was replaced by a larger one with an ice maker. So I redid the tubing again, to tap the filtered water, and ran a plastic tube to the refrigerator. I’m waiting for it to fail, but given the stability of the plastic tubing so far, it probably won’t fail for a long time.
In the future, I will need to replace the failing water stop valve with a dual outlet water stop valve, and maybe redo parts of the plastic tubing again.
Installation Part 1: Installing the Drinking-water Faucet
These mini-faucets are ridiculously expensive, so if you find a kit that includes one, it could save some money. Of course, the kit faucet will break, eventually.
The one I used was a GE UNFCTFBL, which is pretty cheap at $22. The more expensive options look more like fancy faucets.
This unit has a 3/8″ threaded pipe, and comes with a union that connects to the pipe, and presents a push-to-connect or compression fitting for 3/8″ plastic tube.
The problem here is that the water filtration system uses 1/4″ push on connectors for 1/4″ plastic tube.
So my fix was to use a union that went from 3/8″ to 1/4″. You can get these as brass compression unions, which cost less , or buy plastic push-to-connect unions, which are a lot easier to use. 3/8″ tubing went from the faucet to the union. Then, 1/4″ tubing went from the union to the filter.
Installation Part 2: Hook up the Faucet to the Filter Housing
Prep the filter holder by installing a filter. If the canister doesn’t have the push-on connectors, you’re supposed to install some. Get some teflon tape and wrap the threds, and screw them on.
Push the tube from the faucet into the filter housing, on the output side.
Installation Part 3: Tapping into the Water Supply
This is probably the most complicated part, and might be a reason why lower-cost self-install kits aren’t quite as common as in the past. Older houses have copper supply lines and compression fittings. Newer houses have screw-on supply lines that connect to the legacy compression fittings.
However, the old supply pipes were 1/2″ ferrous iron pipe (FIP) coming in from the wall, these went into an angle stop valve, which had a 1/2″ iron pipe (IP) male pipe threads (MPT) output.
Later, the angle stop valves changed to 3/8″ compression fittings, and you can connect your faucet with a supply line that has 3/8″ compression threading at one end, and a 1/2″ IP female (aka FPT) at the other end.
Even later, the FIP fittings were replaced with push-on connectors for plastic hoses. By this time, better hoses had been invented, like PEX. However, the supply lines still tended to use 3/8″ compression.
So, can you tap? The old Kenmore and Ace kits I used had a tee, with 1/2 MPT and FPT at the ends, and a 1/4″ push on at the T. This would be installed under the faucet, and was annoying.
An older tactic is to use a tap that screws onto the supply tube and punctures it to tap in. You can do this only on metal pipes. This works, but you can’t use it on more modern setups.
A relatively easy way to connect to a supply that is 3/8″ compression at one end is to get a supply line with 3/8″ compression at both ends, and a 3/8″ – 3/8″ – 1/4″ reducing tee.
You can attach compression fittings to plastic tube by using a brass compression fitting tube insert. The insert supports the tube so that the compression fitting can be compressed, and squeezed into the tube.
If you find that the angle stop no longer closes, you can replace it with a stop that includes an integrated T, and presents 1/4″ push-on or 1/4″ compression, and a 3/8″ compression.
Once you have tapped into the water supply, connect the plastic tube to the filter.
Step 4: Add Water
Open up the drinking faucet, by flipping the lever up, to relieve some pressure, then start to open the water supply.
Odds are, you’re going to experience some leaks and spray. To stop them, you tighten down the compression fittings. Don’t turn them too hard. Just go 1/8 of a turn at a time.
Once it’s all dry, close the drinking faucet. The system may leak again.