Manitowoc Ice Machine Water Filter Cartridges: How to Match a Filter to Your Model

Start at the nameplate, not the cartridge

A Manitowoc ice machine carries a data plate, usually on the back panel or inside the head section near the control board. It lists the model number, the serial number and the electrical rating. Copy down the model number before you order anything. Serial number ranges matter when a design changed partway through a model’s production, so keep both.

The model number also tells you what kind of cuber you have. A modular head sits on a storage bin or dispenser, and an undercounter unit has its own bin. Which one you have decides how much room there is for a filter head and where the water line enters the cabinet. On a water-cooled condenser, the condenser has its own supply and drain. That line is normally left unfiltered, and only the potable line feeding the water inlet valve and the reservoir passes through the cartridge.

Two machines that look identical from the front can use different filter assemblies, because the water-treatment hardware is often specified separately from the cuber itself. Many sites also fit a filter head and cartridge that were chosen when the machine was installed, and that choice may not match what the current model literature recommends. Check three things: the machine’s model, the filter head already plumbed in, and the part number printed on the cartridge you are replacing. If all three point to the same replacement, order it. If they disagree, resolve that before buying.

Filter head, cartridge body and fitting style

A replacement cartridge has to fit the filter head it screws or twists into. Heads differ in how the cartridge locks in, either with a quarter-turn twist-lock or a threaded canister. They also differ in how the O-ring seals and whether a bypass or purge valve is built into the head. A cartridge with a different cap profile may not seat. A poorly seated cartridge leaks at the head or lets unfiltered water slip past and into the water trough.

Look at the port style on the head as well. Quick-connect fittings, NPT threads and push-in tubing connections are not interchangeable without adapters, and each adapter is another place for a slow drip. The head normally sits on the cold supply line ahead of the water inlet valve, with a shutoff upstream so you can isolate it during a change. When you only swap a cartridge into an existing head, the fittings stay put and the cap profile and O-ring are what you verify.

When you add a new head to a machine that has never had one, confirm the incoming line size and the connection at the machine’s water inlet valve first. Also check that the line has room for a pressure gauge or tee ahead of the head, because a gauge reading before and after the cartridge is the simplest way to see when it is loading up.

What the media actually does

Most ice machine cartridges combine a sediment stage with an activated carbon block. The sediment stage catches sand, rust flakes and pipe scale. Left alone, those particles clog the screen on the water inlet valve and foul the float or level control in the reservoir. The carbon block reduces chlorine and chloramine taste and odor, which would otherwise carry into the ice and, in a bin that feeds a beverage dispenser, into every drink.

Hard water is a separate problem. Dissolved calcium and magnesium deposit as scale on the evaporator plate, the water distribution tube and the sump. Scale slows heat transfer between the refrigerant and the water film. That makes ice release erratically during the harvest cycle and can leave thin or bridged cubes that confuse the thickness probe and the curtain switch. The curtain is the hinged flap the falling slab pushes aside, and a slab that hangs up keeps it from signalling a completed harvest.

Some cartridges add a scale inhibitor, often a polyphosphate that interferes with crystal growth. That is not softening, and it does not remove hardness. If your water test shows high hardness in grains per gallon, a scale-inhibiting cartridge helps, but a dedicated softener or a different treatment plan may still be needed upstream.

Ratings that decide the purchase

Check the micron rating, which describes the size of particle the sediment stage targets. A finer rating catches more but loads up sooner and increases pressure drop across the cartridge. A cuber needs enough inlet pressure and flow to refill the reservoir during each freeze and harvest cycle, so a cartridge sized for lower flow can starve a high-output machine. Compare the cartridge’s flow rate in gallons per minute with what the machine needs rather than assuming any cartridge that screws in will keep up.

Capacity is stated in gallons of treated water, and real life usually comes in lower than the label when sediment is heavy. Look for NSF/ANSI listings that match your goal: Standard 42 covers aesthetic effects such as chlorine taste and odor, Standard 53 covers health-related reductions, and Standard 372 addresses lead-free materials. A listing applies to the specific cartridge, so read the exact product page instead of trusting the brand name alone.

Be careful with cross-brand part numbers. A cartridge sold for a Hoshizaki, Scotsman or Ice-O-Matic machine may share a thread and a cap shape with a Manitowoc head yet differ in flow rating, media or scale-inhibitor content. A listing that names your Manitowoc model or the head it fits is a better basis than one that only says it fits most commercial ice machines.

Mistakes that cost you a service call

The most common error is buying by appearance. A generic cartridge with the right thread but the wrong flow rating or media can produce cloudy ice, slow production or a low-water fault on a freeze cycle that never fills the sump. Another is skipping the flush. New carbon fines can cloud the first ice and clog the inlet valve screen, so run water through the new cartridge to purge air and fines before the machine refills the reservoir. Trapped air in the head can also make the machine look short on water.

Overrunning the change interval is the other expensive habit. A loaded sediment stage restricts flow, a depleted carbon block stops removing chlorine, and an exhausted scale inhibitor lets deposits form on the evaporator and distribution tube. Record the install date on the housing and change on the calendar or on the gauge reading, whichever comes first.

Cartridge changes belong inside a preventive maintenance routine, but they do not replace the other tasks. Cleaning and sanitizing use the cleaner and the sanitizer named in that model’s manual. A bottle marked nickel-safe is not automatically the right chemical. Checking the curtain switch, the water pump, and the water level control is separate work too. A new cartridge will not remove scale already on the evaporator, and a cleaning will not restore a depleted carbon block.

Matching the cartridge to your site

A busy kitchen with chlorinated municipal water, a bin that feeds a soda fountain, and moderate hardness has different needs from a low-volume office with well water. In the first case, carbon capacity and taste reduction decide the purchase. In the second, sediment loading and iron or hardness decide it. Check a local water report or run a test strip for chlorine and hardness before choosing between a basic sediment-and-carbon cartridge and one with scale inhibition.

Once you have the model number, the existing head and your water conditions, the choice usually narrows to one or two replacement cartridges. Keep a spare on the shelf so a change does not wait on shipping, and store it sealed and out of heat so the media stays in good condition.

Cartridge numbers are not one list

Manitowoc has published more than one ArcticPure cartridge sheet. The part numbers do not line up, so the number on the head wins.

The older ArcticPure performance sheet lists these cartridges:

That sheet lists 1.0 micron media, 0.75 gpm for the AR-10000 and AR-20000, and 1.5 gpm for the AR-40000. It says to change the primary cartridge at least every six months, and sooner if a gauge ahead of the cartridge reads below 20 psig.

A later cartridge sheet uses different numbers for the same head names: K00540 for AR-10000, K00541 for AR-20000, and K00542 for the prefilter. It shows the AR-40000 taking two cartridges. It rates those primary cartridges at 5 micron, not 1.0. It says K00540, K00541, and K00542 were tested to NSF/ANSI Standard 42 and CSA B483.1 for material and structural integrity. That is not the same claim as the older sheet, and it does not transfer to a cartridge from the other sheet.

Do not treat K00339 and K00541 as the same part. A Plus head is another family. Read the label on that head. The replacement instruction for K00337, K00338, and K00339 is a different document from the K00540-series sheet. The ArcticPure performance data is the older list.

Both sheets still say to replace the cartridge at least every six months, or sooner when flow drops off. Keep the housing from freezing. Manitowoc says a frozen housing can crack and leak.

Look up the number you read off the head. A result that only says it fits most commercial ice machines is not a match.

Confirm the part number on the listing before you buy. How to match the filter head covers the head, the fittings, and the flow check. Cleaning is a different chemical. See cleaner, descaler, and sanitizer.

Related guides

• Match the filter head before you buy the cartridge
• Cleaner, descaler, and sanitizer are three different chemicals

FAQ

Can I use any ice machine filter cartridge in a Manitowoc machine?

No. The cartridge has to fit the filter head, match the fittings, and supply enough flow for the machine’s fill cycle. Check the model number on the nameplate and the part number on the cartridge you are replacing before you order.

How often should the cartridge be changed?

Follow the cartridge’s rated capacity and the interval in the machine or filter literature, and change sooner if you see a pressure drop, cloudy ice or a chlorine taste. Heavy sediment or hard water shortens the life of the cartridge. Writing the install date on the housing makes the schedule easy to keep.

Does a filter cartridge replace descaling the machine?

No. A scale-inhibiting cartridge slows deposit buildup but does not remove scale already on the evaporator plate or in the water distribution tube. The machine still needs the cleaner and sanitizer named in its manual.

Are K00339 and K00541 the same cartridge?

No. They show up on different Manitowoc sheets for ArcticPure heads. Order the number printed on the head and on the cartridge you are removing.