Door Knob Lock Replacement

A door knob with lock can fail in several distinct ways, and the right response depends on the failure mode. A spinning knob with no resistance usually means the set screw has backed out or the spindle has sheared inside the chassis — often repairable on the spot. A key that turns but the latch does not retract points to a worn cam or a broken tail-piece inside the cylinder, which typically means replacing the cylinder or the full knob set. Corrosion, a common problem on Larchmont properties close to the Long Island Sound where salt air accelerates metal fatigue, can freeze the plug so completely that no amount of lubrication saves it. In that situation, a full door knob lock replacement is the cost-effective path forward.

Exterior knob sets on rental properties, home offices, and small commercial suites on Boston Post Road also wear faster than interior sets because they see more daily cycles and exposure to weather. Our technicians assess the door prep — the diameter of the bore hole, the backset measurement, the strike plate condition, and whether the door is solid core or hollow core — before recommending a replacement grade. Upgrading to a higher-security knob with lock and key at that point costs little extra in labor and delivers meaningfully better protection.

Older Larchmont residences, particularly the Craftsman and Tudor-style homes in the Manor and Flint Park neighborhoods, were often fitted at the factory with mortise lock assemblies rather than the cylindrical bore sets most people picture when they think of a door knob or lever trim. A mortise lock is a full cartridge — latch bolt, dead bolt, and sometimes a night latch — recessed into a rectangular pocket cut into the door edge. Replacing one is a fundamentally different job from swapping a cylindrical knob set: the cartridge must be extracted, the new unit aligned precisely to the existing pocket, and the trim roses and lever handles fitted so the spindle engages the cam without binding.

Our technicians carry mortise lock bodies in both standard and narrow-stile dimensions, along with escutcheon plates that cover the old mortise outline when a homeowner is upgrading to a modern profile. We also handle the reverse situation — a property owner who wants to restore period hardware on a historic door will have us fit a new-old-stock or reproduction mortise cartridge to keep the aesthetic intact. Either way, the work is performed damage-free where the existing door and jamb allow, meaning we do not drill new holes unless the measurement truly demands it. For any mortise lock job that involves exterior doors, call us at 914-670-1446 — we are available around the clock.

Residential replacements cover the full range from a basic interior door knob with lock for a bedroom or bathroom to a Grade 2 keyed entry set on a side door. Our technicians install Schlage, Kwikset, and other recognized hardware lines, and we can key multiple new knobs alike so one key opens every door on the property — a popular request among homeowners who have accumulated a ring of different keys over years of piecemeal upgrades. We also handle double lock door knob configurations where both the knob and a separate dead latch are keyed independently, a setup common on garden-level apartment entries in Westchester where an extra barrier matters.

Commercial clients along the Palmer Avenue corridor and in Larchmont's professional office buildings often need lever sets rather than knobs to meet ADA accessibility requirements, and those levers must be paired with the correct latch function — passage, privacy, storeroom, or classroom — to suit the space. Our commercial locksmith work includes installing heavy-duty Grade 1 lever sets on high-traffic doors, rekeying an entire suite when staff turnover happens, and replacing failed mortise lock cartridges in older office suites without disturbing the surrounding millwork. As an emergency locksmith resource, we also respond when a commercial lock fails mid-business-day and the door will not secure properly, because leaving inventory or client files unprotected is not an option.

Several variables shape the final quote for any door knob lock replacement or mortise lock job. The primary factors are the grade and brand of hardware selected, the complexity of the existing door prep, the time of day the call comes in, and the travel distance to your Larchmont address. A straightforward cylindrical knob swap on a standard 2-3/8 inch backset interior door is a simpler job than extracting a seized mortise lock from a 100-year-old exterior door with a non-standard pocket depth, and the quotes reflect that difference honestly. We never begin work without confirming the exact price with you first — no surprise charges appear on the invoice.

When you call 914-670-1446, the dispatcher will ask a few quick questions: the door type, whether it is interior or exterior, roughly how old the hardware is, and whether you prefer a specific brand or finish. That information lets the technician arrive prepared with the most likely replacement parts already on the truck, keeping the appointment efficient. If the assessment on-site reveals a complication — say, a non-standard backset or a stripped strike plate box that also needs attention — we explain what was found and get your approval before any additional work begins. Our goal is zero surprises on the invoice and a door that operates correctly when we leave.

Search traffic shows that many people arrive on pages like this after searching how to pick a door knob lock because they are locked out and looking for any solution. We understand that urgency. However, attempting to pick or bypass a lock without the right tools and training almost always results in a damaged plug, a broken tension wrench stuck in the keyway, or a scratched finish — turning a simple lockout into a full replacement job that costs significantly more. Beyond that, improper bypass attempts on a door knob with lock can deform the cam mechanism so that even a professional has difficulty extracting the cylinder cleanly afterward.

The safer path is to check first: is there a spare key with a neighbor, a building manager, or a family member? Is there another entrance — a back door or sliding door — that is accessible? If you are also dealing with a sliding door lock replacement on a patio entry, our technicians handle those as well, so one call can cover multiple access points. If no alternative exists, call us at 914-670-1446 — we verify ownership or occupancy on-site as part of standard procedure, then use professional tools to open the door with minimal or no damage before recommending whether the existing lock knob should be rekeyed or replaced entirely. We are available every hour of every day, including holidays.