PUR CR1 Filter CRF950Z: The Standard Replacement
The PUR CR1 filter (part CRF950Z) is the standard replacement filter for all PUR gravity dispensers and most PUR pitchers. It combines activated carbon for chlorine taste and odor reduction (NSF 42) with ion-exchange resin for lead and mercury reduction (NSF 53). Lead reduction claim: greater than 99% at 150 ppb under NSF 53 test conditions. Mercury reduction: greater than 97% at 2 ppb under NSF 53 test conditions. Rated for 40 gallons (approximately 150 liters). Replace every 40 gallons or 2 months, whichever comes first. Price is $9-12 per filter at retail; multi-packs of 3 or 6 reduce per-filter cost by 15-20%.
PUR+ Maxion Filter FM-9000B: Expanded Contaminant Coverage
The PUR+ Maxion filter (part FM-9000B) adds NSF 401 certification for emerging contaminants to the base NSF 42 and NSF 53 certifications of the CR1 filter. NSF 401 covers trace pharmaceuticals, personal care product compounds, pesticides (atrazine), and herbicides (linuron) at the tested concentrations. Rated for 100 gallons -- 2.5 times the capacity of the CR1. Price is $14-16 per filter, but the longer life means annual filter cost is lower than with the CR1 for households with above-average consumption. Confirm Maxion compatibility with your specific dispenser before ordering -- the DS-1800Z accepts the Maxion filter; not all DR Series models do.
DS-1800Z Tap (Spigot) Maintenance
The front-mounted spigot on the DS-1800Z is the only mechanical wear part outside the filter. The spigot uses a simple rotating valve with a rubber O-ring. If the spigot drips at the base when closed, the O-ring has deformed. PUR includes a replacement O-ring in some retail packaging, but does not sell the O-ring as a standalone part. A 1/4-inch ID by 3/8-inch OD nitrile O-ring from a hardware store is the correct match. Remove the spigot by pressing the release tab and pulling outward, swap the O-ring on the valve stem, and reinsert the spigot until it clicks. Replacement takes under 5 minutes without tools.
Filter Storage and Shelf Life
PUR CR1 filters stored in the original sealed packaging have an indefinite shelf life -- the activated carbon and ion-exchange resin do not degrade in dry, sealed storage. Once installed and wetted, the filter begins aging and should be replaced within 2 months regardless of gallons filtered. Do not store a wet, used filter out of the dispenser for more than 2 days -- removed wet filters can develop bacterial growth in the damp media within 48-72 hours. If you remove the filter from the dispenser for cleaning, reinstall it immediately and do not allow it to dry out, as re-wetting a fully dried carbon block can cause channeling and reduced filtration effectiveness.
Electronic Indicator Battery Replacement
PUR DS-1800Z and DR Series filter change indicators are powered by a sealed CR2032 coin cell battery. Battery life is 3-5 years under normal use. When the indicator LED fails to illuminate after pressing the reset button, the battery is depleted. Open the indicator housing on the rear of the dispenser lid by pressing the release tab, remove the old CR2032, and insert a new cell with the positive (+) face up. Coin cells are available at any hardware store or pharmacy for under $2. Replace the battery and reset the filter indicator before reusing the dispenser.