How to Fix a Leaking Gate Valve
Updated February 20, 2026
Stop a dripping gate valve stem -- tighten the packing nut, replace the packing, or swap the whole valve for a ball valve, depending on what the situation calls for.
Overview
Gate valves -- the round-handled shut-off valves in older homes -- have one very common failure mode: they drip at the stem. Water seeps out around the handle or from the packing nut just below it. This happens because the packing material that seals around the stem deteriorates over time, especially on valves that sit in one position for years without being touched. The fix is often as simple as tightening the packing nut -- literally a 5-minute job. If that does not stop it, replacing the packing takes 15-30 minutes. Full valve replacement is only on the table if the body is cracked or the gate mechanism has failed.
What You'll Need
Safety First
- You do not need to shut off the water to tighten or repack the packing nut -- it can be done under pressure. But if you are replacing the entire valve, you have to shut off the water upstream (main shut-off or a valve closer to the meter).
- Gate valves that have not been touched in years can seize solid. Do not force a stuck one with a wrench on the handle -- the handle can snap, the stem can break, or the body can crack. If it will not turn, see our stuck shut-off valve guide for safe techniques.
- Small adjustments only on the packing nut -- 1/8 turn at a time. Overtightening compresses the packing too much, makes the handle nearly impossible to turn, and can crack the nut.
Step-by-Step Instructions
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Identify the Source of the Leak
Dry the valve completely with a towel and watch where water shows up. Three possibilities: the packing nut area (just below the handle where the stem exits the body -- most common), the valve body itself (a crack or pinhole in the brass or iron -- rare but means full replacement), or the pipe connections (threaded or soldered joints where the pipes meet the valve -- that is a pipe problem, not a valve problem). Packing nut leak? Keep reading. Cracked body? Replace it. Pipe connections? See our pipe repair guides.
Tip: Packing leaks often only show up when the valve is partially open or right after you turn it. If it drips from the stem area only when you operate it, the packing is definitely the cause. -
Tighten the Packing Nut (5-Minute Fix)
The packing nut is the hex nut right below the handle where the stem enters the body. Use an adjustable wrench and turn it clockwise 1/8 to 1/4 turn. That compresses the packing tighter around the stem and restores the seal. Check if the drip stops. If it does, you are done. If it slows but does not stop, give it another 1/8 turn. Do not go more than 1/2 turn total without checking -- overtightening makes the handle stiff and can crack the nut. After tightening, turn the handle back and forth to make sure it still operates.
Tip: This fixes about half of all gate valve stem leaks. Takes less than a minute and it is always the first thing to try. If the packing is severely deteriorated from a long-standing leak, tightening alone will not cut it -- move on to repacking. -
Replace the Packing Material (If Tightening Does Not Work)
Tightening did not work? The packing itself needs replacing. Keep the water on -- just open the valve fully to relieve pressure on the packing area. Unscrew the packing nut completely and slide it up the stem. You will see the old packing wrapped around the stem -- it could be string-like graphite packing, a rubber O-ring, or a wax/graphite washer. Pull all of it out. Wrap new graphite packing string around the stem clockwise (so tightening the nut does not unwind it), 3-5 wraps depending on the space. Push the packing down into the cavity with a flathead screwdriver if needed. Slide the nut back down and tighten finger-tight plus 1/4 turn with a wrench. Check for leaks.
Tip: Graphite packing string (also called valve packing rope) is the go-to material -- it conforms to any stem size, handles heat, and lasts for years. PTFE (Teflon) packing string works just as well. Either one is under $5 at any hardware store and a single roll handles dozens of repairs. -
Replace the Entire Valve (If Packing Does Not Fix It)
Body cracked, gate will not close, or the valve is too far gone for repacking? Full replacement time. Shut off the water upstream. For threaded gate valves, use two pipe wrenches -- one to hold the pipe, one to turn the valve -- and unscrew it. Wrap the threads with Teflon tape and install a quarter-turn ball valve in its place. Ball valves are a major upgrade: more reliable, will not seize, and close with a single 90-degree turn instead of cranking a handle around multiple times. For soldered gate valves, cut the pipes and use SharkBite push-fit connectors to install the new ball valve -- no soldering needed.
Warning: Always use a backup wrench to hold the pipe when unscrewing a threaded valve. Without one, the torque twists the pipe and can crack it further down the line -- especially with old galvanized steel. That turns a simple valve swap into a much bigger repair. -
Test and Verify the Repair
Dry the area and check for leaks. Open and close the valve through its full range several times. Repacked valve too stiff? The packing nut is overtightened -- back it off 1/8 turn. Replaced valve? Check every connection (threaded or push-fit) under full pressure. Let the system sit pressurized for 10 minutes and reinspect before you call it done.
Tip: Replaced a gate valve with a ball valve? Label it with its function -- 'Main Water' or 'Kitchen Supply' -- using a marker or tag. Makes it easy to find the right valve fast in an emergency.
Pro Tips
- Any time you replace a gate valve, upgrade to a ball valve. Gate valves seize, corrode internally, and fail. Ball valves are more reliable, easier to operate (one 90-degree turn instead of cranking), and far less likely to seize from sitting unused.
- Exercise your gate valves once a year -- turn them fully closed, then fully open. This keeps the packing from bonding to the stem and the gate from seizing. A gate valve that sits untouched for 5+ years is almost guaranteed to seize or leak when you finally need it.
- Keep a roll of graphite packing string in your toolkit. It fixes leaking stems on gate valves, globe valves, and outdoor hose bibs. A single $3 roll lasts for dozens of repairs.
- Emergency stopgap: if you do not have packing material, a few wraps of Teflon tape around the stem under the packing nut can hold for days or weeks while you get proper packing.
- If you are doing any plumbing renovation, replace the main shut-off gate valve with a full-port ball valve. A seized gate valve during a burst pipe emergency turns a manageable situation into a disaster.
When to Call a Pro
Tightening and repacking are easy DIY. Call a plumber if the valve is on the main line and you are not comfortable working with the whole house shut off, if the pipes are old galvanized and you are worried about cracking them, if the valve is soldered into copper and you do not have soldering or SharkBite experience, or if multiple valves need upgrading at once.