Step 1: Decide Between Bottled and Plumbed
Bottled coolers (WFC-1001, WC18BEK) require no water line connection -- you place the unit, load a bottle, and plug in. They suit renters, offices without under-sink access, or homeowners who want portability. Under-sink RO (WHER25) requires a cold water supply tap, a drain connection, and a sink hole for the dedicated faucet. Once installed, WHER25 delivers unlimited filtered water without bottle logistics. If you have a utility room or open under-sink cabinet with cold water access, WHER25 is the economically superior long-term choice.
Step 2: Top-Load vs. Bottom-Load Cooler
Top-load WFC-1001: requires lifting a 5-gallon bottle (approximately 42 pounds full) and inverting it onto the neck collar. Bottom-load WC18BEK: the bottle stays upright in the cabinet; an electric pump draws water up. Bottom-load units add $50-100 to the purchase price but eliminate lifting, making them the preferred choice for users with back issues, elderly residents, or anyone who will change bottles without help. Both units provide identical hot and cold output temperatures -- the bottle loading mechanism is the only functional difference.
Step 3: Evaluate Water Quality for RO Applicability
WHER25 RO is warranted when your tap water contains detectable nitrates (above 5 mg/L), fluoride concern, arsenic in well water, or elevated total dissolved solids (TDS above 500 mg/L). Have your water tested by a certified lab -- many county extension offices provide free or low-cost water quality tests. If your municipal water is below these thresholds, a gravity filter or faucet filter may be sufficient and less expensive. If your water tests above, the WHER25 is the appropriate treatment level.
Step 4: Calculate WHER25 Installation Requirements
WHER25 requires: a 3/8-inch cold water supply connection (typically tapped from the cold shutoff valve under the sink), a drain saddle adapter for the reject water line (drills into the drain P-trap), a 1.375-inch hole in the sink deck for the dedicated faucet, and under-sink space to mount the filter housing and 2-gallon pressure tank. The filter housing is 15.5 inches tall; the pressure tank is 11.5 inches tall. Measure your under-sink cabinet height and width before ordering -- cramped cabinets may require relocating the drain line or positioning the tank horizontally using an optional horizontal kit.
Step 5: Budget Total Cost of Ownership
WHER25 initial purchase is $150-200. Annual filter replacement: sediment + carbon pre-filters (replace at 6-12 months) at $25-40 per set; carbon post-filter (replace annually) at $15-25; RO membrane (replace every 2-3 years) at $30-50. Total annual operating cost is approximately $60-90. Compare to a bottled delivery service at $30-50 per month ($360-600 annually). WHER25 achieves full payback within the first year of operation for most households.