Main Water Shut Off Valve Leaking: Tips for Repairing It

Main water shut off valve leaking is a common problem. The valve may be absolutely new, you may have just installed one or it could have been your plumber who had installed it a few days back. It could also be a very old valve in which case it is likely to be damaged or worn down. Depending on the exact cause of the main water shut off valve leaking, you may choose to replace it or you can just take a few corrective steps to fix it.

Find the Cause

Let us first understand the cause of the main water shut off valve leaking. You would find obvious signs of the leak when you check the valve under a toilet or sink or one in the basement. As you open and close the valve, it may leak a little. There may be steady drips. A very severe leak is unlikely unless the valve fails completely. There are two things you can do. You can tighten the packing nut or you can replace the packing washer.

To tighten the packing nut, all you need is a wrench. Tighten the nut and check if there are any leaks. If the leak persists, tighten the nut a little more. Resist from tightening the nut too much as it can take a toll on the threads. You don’t want to damage the nut or the valve.

Perform Necessary Replacements

If this doesn’t solve the problem then you need to replace the packing washer. Even a new valve can leak, particularly around the handle when you turn it. The valve stem may have a problem, the washer may be worn out, the watertight seal may have been compromised as a result and the problem could be more than one of these. A damaged packing washer will need to be replaced.

To replace a packing washer, you must first turn off the supply of the water. Uninstall the handle, loosen the stem and pull out the packing nut. Remove the washer and get a new one in. You must be ready with a new and identical packing washer to complete the job. Reassemble the whole system and ensure all components are optimally tightened.

Turn on the water supply and check for leaks. If there are no leaks, then you have solved the problem. If there is a leak then the packing nut needs a bit more tightening. A new packing washer should resolve the problem. If it doesn’t, call in your plumber.

Skip to content