3M Aqua-Pure AP431 Whole House Scale Inhibition Inline Replacement Water Cartridge For System AP430SS, Genuine 3M Replacement Cartridge

Just what I needed.

The installers of my gas boiler put this scale inhibition system in along with everything else so I just needed the replacement cartridge. It fit perfectly with no threading issues others have mentioned, went right in first time and sealed tight, no leaks. Did not use Teflon tape as it is not needed for the cartridge.

Our house has a water softening system, so when I saw that the current filter was 7/8 years old when we purchased our home, I wasn’t too worried about the filter. After living here for 2 1/2 years, we have accidentally let the saltwater brine tank run out a few times, so hard water has made it through. After flushing our instant hot tankless water heater with 2 gallons of vinegar, I saw how much calcium scale was actually in there. So, I decided to purchase a new pre-filter, especially when my plumber friend suggested it would probably be a good idea. However, he said we probably won’t need to replace it again for a number of years, as long as we don’t let the brine tank run out very often 😆

The first one that I ordered leaked on me. It was a small leak but nothing I tried help. Put lots of thread tape changed the brass nipple twice.. and nothing and it still had a small leak.. called amazon customer help and they send me a replacement the next. Day. The Second one I put a new nipple brass pipe and plenty of thread tape and no leaks. Happy with my Purchase and Amazon for always been helpful with returns or exchanges. I. Will update later to see how good it works.

Great

Excellent product, easy to install. Hopefully it will help my water heater last longer.

We had this unit installed by a plumber as a part of a tankless water heater install. I failed to flush the heater at the one year mark due to health issues but did at 2 years. We have very hard water and my expectations were for a significant scale to show up during the flush but actually had very little. We use this downstream from our water softener unit due to our water hardness.I did note that the new cartridge was EXTREMELY difficult to NOT cross thread during installation. Take your time and be very careful. A method I use for this type of situation is to place the threaded piece into the socket and gently rotate it counter clockwise until I can feel the the first thread "click" slightly as it passes the first thread then start threading into the socket in a clockwise manner. Carefully observe that the cartridge is going in straight and threading in EASILY. The easy threading is critical. The threads on the plastic cartridge don't form the seal, the o-ring does. If the threads bind at all you are likely starting to cross thread. If that happens back out and try again. It took me 3 tries to get the cartridge to thread easily because the way we have ours mounted its at about waist level to me. By getting a lower view and being level with the socket I was able to easily tell when the threaded portion was not going in straight.

Works with magic and unicorn tears. :o)It is not a filter. It is a water treatment system.The stainless steel head is robust and a nice solid chunk of metal. Easily could withstand brazing/soldering, on the spot, with the cartridge off.The 3/4" NPT inlet and outlet has nearly a clear flow path, so your GPM, will not be reduced. Install a ball or gate valve in front to permit easy cartridge changeouts.The tee must be orientated to the water flow, use the arrow on the side of the tee, for the water to get treated while flowing.There is an elevated tab in the tee with a single hole for directing a small portion of the water down into the center whole of the cartridge.The water slowly dissolves a small amount of food-grade polyphosphate from the beads and, using the venturi effect, the water is then pulled back through the 8 holes in the cartridge perimeter and through the 3 holes in the tee, surrounding the center tab, to mix with the flowing water.Only 2 to 3 ppm is needed to treat for scale.From past uses at a different home, I've gotten about 20,000 gallons out of a cartridge with still some beads rattling in the bottom when replacing the cartridge.I would say that if you used less than 2,000 gallons a month then one cartridge should easily last a year.The cartridge threads are plastic and you can easily cross-thread them if you get in a hurry replacing the cartridge. Just make sure you get the threads started straight and it screws up with no problems.The threads do no provide the seal, it is the o-ring so once hand-tight that is tight enough.