Waterdrop Direct Connect: the under-sink filter on your existing faucet

Direct Connect at a glance

As read on October 14, 2026, the Direct Connect WD-10UA was $58.99, the WD-15UA $76.99 and the WD-17UA $95.99, sold by filter capacity of 11,000, 19,000 and 24,000 gallons, for the cold line only. It is an under-sink filter with no RO membrane and no drain line, rated 0.75 GPM, and its spec block lists NSF/ANSI 42 and 372.

Waterdrop also sells an ultrafiltration version at $69.99, $79.99 and $99.99 for the same three capacities.

• WD-10UA: 11,000 gallons, $58.99.
• WD-15UA: 19,000 gallons, $76.99.
• WD-17UA: 24,000 gallons, $95.99.

Where it connects

Waterdrop says the WD-UA connects to your original faucet, and that the WD-UB comes with its own faucet, which goes into the original faucet hole or a drilled 1-inch hole. The filters are designed for cold water lines only, at 10 to 125 psi.

With no membrane, nothing goes to a drain. It is still a plumbing connection under the sink, so a renter can use it only where the lease allows one; countertop RO needs none (see Waterdrop countertop RO).

What the certification line covers

Waterdrop's page says the filter reduces chlorine, odor, sediment and heavy metals, third-party tested, and is NSF/ANSI 42 and 372 certified. IAPMO R&T's directory lists the WD-10UA, WD-15UA and WD-17UA under NSF/ANSI 42 for aesthetic chlorine, taste and odor, and in its lead-free certificate.

NSF/ANSI 42 is the taste-and-odor standard, and Waterdrop's NSF page says it asks for at least a 50% cut in chlorine. No NSF/ANSI 53 or 58 line is printed for Direct Connect, so its heavy-metals wording is Waterdrop's own test claim; RO vs carbon filter covers what an RO system adds.

Filter life, the TSA step up, warranty and returns

The capacity is the filter's rated life: 11,000, 19,000 or 24,000 gallons by size. The next step under the counter is Waterdrop's 3-stage TSA, $139.99, rated 1 gallon per minute with NSF/ANSI 42 and 372 on its spec. The TSA-UF, $149.99, lists NSF/ANSI 372 only and no need for electricity, although its FAQ calls it a tankless RO system that reduces TDS and PFAS; its name describes ultrafiltration.

Direct Connect shows a 1-year warranty badge. Waterdrop's service policy allows returns within 30 days of receipt for orders in the continental United States; you pay return shipping unless the return is for a quality issue, and items not returned in like-new condition carry a 10% restocking fee.