Whirlpool WHER25 Filter Replacement and Annual Cost
WHER25 replacement filters: sediment stage (WHKF-WHSEDW, $8--$12, 12-month); carbon stage (WHKF-WHCAR, $10--$15, 12-month); RO membrane (WHER25-R, $25--$40, 2 years). Annual cost excluding membrane: $18--$27 -- the lowest annual filter cost in the under-sink RO category, reflecting the simpler 3-stage design and smaller membrane. All Whirlpool WHER25 replacement parts are available at Home Depot, Lowe's, and Amazon. Whirlpool EveryDrop refrigerator filters: replace every 6 months or 200 gallons -- refrigerator control panel displays the replacement reminder. Annual cost for two filter changes: $60--$100 OEM, $20--$50 third-party.