How to Loosen Faucet Mounting Nuts

Old faucet mounting nuts locking the faucet into place can be tricky to remove, especially worn-out ones. Suddenly the quick thirty-minute faucet fix turns into a lengthy escapade that is draining your precious little time by the minute.

Try these quick tips to loosen the faucet mounting nuts before throwing in the towel and calling a professional plumber.

Removing Faucet Mounting Nuts

The mounting nuts are accessible after you have removed the handles and escutcheon out of the way. These are the nuts holding the faucet body in place. Before trying any of the below methods, use channel-type pliers or an adjustable wrench to remove the nut by turning it counterclockwise.

Stubborn mounting nuts are bad enough, but add plastic into the mix, which can be even worse. If you’re dealing with a stuck faucet nut that refuses to budge, here are a few methods you can try that might help loosen the mounting nuts.

Removing Faucet Mounting Nuts

It is important to note that several of these methods will destroy the mounting nut, so you’ll need a replacement if you are keeping the faucet assembly.

Method 1: Try A Basin Wrench

A basin wrench is a handy tool to have on hand while tinkering with faucets. In some cases, it can be the ideal faucet mounting nut removal tool. It can reach into tight spaces, like those behind the sink where an ordinary wrench doesn’t have room to maneuver around. If you have a basin wrench on hand, use it to try to remove the mounting nuts.

Here’s what you’ll need:

  • Basin wrench
  • Headlamp

Remember to shut off the water supply valve before disassembling the faucet. Drain the water from the faucet by turning on the tap. It’s easier if you clean out the cabinet beneath your sink so that you have plenty of room to work.

Once the water supply is off and the cabinet is clean, put on your headlamp and crawl under the sink. Open up the wrench jaws, then insert the pole up behind the sink and hook the jaws onto the nut.

Ensure that they are positioned facing the direction you need to turn (counterclockwise). This way, the jaws will automatically secure onto the nut. Firmly grasp the wrench handle and attempt to turn the nut. The wrench handle should extend far enough below the sink that you can grip it with both hands.

Some faucet mounting nuts are shaped in a way that prevents the wrench from firmly gripping the nut. If that is the case, try one of the following options.

Method 2: Screwdriver And A Hammer

Certain types of mounting nuts have plastic nibs along the surface. Although they prevent the basin wrench from doing its job, they provide a spot to lodge a flat-head screwdriver.

For this method, you’ll need:

  • Flat-head screwdriver
  • Hammer
  • Headlamp
Screwdriver And A Hammer

Position the flathead screwdriver against one of the plastic nibs. Use the hammer to tap the end of the screwdriver to loosen the nut. It might be tricky to get a good angle with the screwdriver. However, if you can maneuver it in any way that is perpendicular to the washer, you may be able to loosen the nut.

On older sinks, the faucet mounting nuts may have developed substantial mineral deposits in the threads. If that is the case, try tapping it in the other direction before unscrewing it. This will help break the calcium bond fixing it in place, which will help you loosen the nut.

Method 3: Heat

Heat is a helpful tool when trying to remove stubborn plastic faucet mounting nuts. You can try using heat in tandem with either of the aforementioned methods, as the heat may help soften the nut.

For this method, you’ll need:

  • A hairdryer, heat gun, or propane torch
  • Flame resistant fabric (if using anything flammable)

If you use a propane torch, ensure that you shield anything flammable from the flame. Use the heat source of your choice to heat the nut, then allow it to cool slightly. Before it completely cools, try to dislodge the nut using either of the above methods.

Method 4: Soak The Nut

If the nut is still firmly fixed in place, try a calcium dissolver, lubricant, or penetrating oil. Calcium dissolver, when used in conjunction with method one or two, can help loosen the bond.

For this method, you’ll need:

  • Calcium dissolver
  • WD-40
  • Penetrating oil
  • White vinegar
  • Wire brush

If the nut is encased in white lime deposits or rust, use a wire brush and vinegar to remove it. Scrub the area first with the wire brush and remove as many of the deposits as you can. Dab white vinegar onto the remaining deposits, then allow it to dissolve. Wipe away the residue with a clean towel.

White vinegar

Once you have removed any buildup around the nut, squirt a penetrating oil on the threads. Allow it to soak in. The longer you wait, the better. If you don’t need to remove the nut right away, apply several coats over 24 hours. Then, try to loosen the nut.

You can also try a calcium dissolver alongside the first two methods. It should help loosen and break down the calcium bond that may be causing problems. Otherwise, try using a lubricant, like WD-40, to loosen the nut.

Many types of lubricant and penetrating oil are flammable, so ensure that you don’t use heat in conjunction with them. If you did use either and are resorting to heat to remove the nut, ensure that you thoroughly clean the area with a water-based degreaser and a clean cloth.

Method 5: Cut Through The Nut

If all else fails and you have tried all of the above steps, you may have to resort to slicing through the nut with a hacksaw or reciprocating saw.

For this method, you’ll need:

  • Protective gear
  • Reciprocating saw or hacksaw
  • Flathead screwdriver

Make a vertical cut up through the nut with either the reciprocating saw or hacksaw. Wedge the flathead screwdriver into the fissure and pry the ends apart. You should be able to remove the nut.