Why is my new faucet dripping after install in my Ottawa bathroom?

A dripping faucet after a new install almost always comes down to one of three things: improper seating of the cartridge or valve, missing or damaged washers/O-rings, or incorrect installation of the supply connections. The good news is that most of these issues are fixable without starting over completely.

The most common culprit in a brand-new faucet install is the cartridge not being fully seated. Modern single-handle faucets use a ceramic disc or cartridge mechanism that needs to click firmly into place and be oriented correctly. If it's even slightly off-axis or not fully inserted, you'll get a persistent drip from the spout even when the handle is fully closed. The fix is usually to shut off the supply valves under the sink, remove the handle, and reseat or reorient the cartridge — often there's a small tab or flat edge that aligns with a slot in the faucet body.

Damaged or missing O-rings are another frequent issue, especially if the faucet was handled roughly during shipping or installation. Check the rubber components that came with your faucet — most manufacturers include spares in the box. Even a small nick in an O-ring from a utility knife during unpacking can cause a slow drip. Also worth checking: did you use plumber's tape (Teflon tape) on the threaded supply line connections? Three wraps clockwise on the threads before connecting the supply lines is standard practice and prevents seeping at the base.

Ottawa's water pressure is also worth considering here. The City of Ottawa's municipal water pressure typically runs between 60–80 PSI in most neighbourhoods, and some older areas closer to the core can run higher. High incoming pressure can expose a weak cartridge seal that might hold fine at lower pressure. If your faucet is dripping and you've confirmed the install looks correct, a pressure reducing valve (PRV) check might be worthwhile — anything over 80 PSI can stress faucet components and void manufacturer warranties.

From a DIY standpoint, reseating a cartridge or replacing an O-ring is a reasonable homeowner repair — just make sure both supply valves under the sink are fully closed before disassembling, and take a photo of the cartridge orientation before pulling it out. However, if you're seeing water dripping from the base of the faucet rather than the spout, or if there's moisture around the supply line connections, address that quickly — even slow leaks can damage cabinet interiors and subfloor over time.

Your next step is to identify exactly where the drip is coming from: the spout, the base, or the supply connections. That location tells you which component needs attention. If you've already reseated the cartridge and replaced the O-rings and it's still dripping, the faucet itself may be defective — most brands have a warranty process for this.

If this is part of a larger bathroom renovation or you'd rather have a professional handle the plumbing side, Justyn Rook Contracting works with licensed plumbers on full bathroom projects. For a standalone plumbing fix, we'd recommend reaching out to James McGee at A Helping Hand Residential Plumbing — a trusted Ottawa plumber for exactly this kind of issue.