Troubleshooting Plastic Compression Fittings

Throughout your home you will find plastic compression fittings, at just about any location where you have a sink or a source of tubing that holds water, gas or lubricant. While these make repairs easy, they also make repairs necessary more often. There are many reasons why plastic compression fittings are subject to leakage. Learn these handy tips for troubleshooting plastic compression fittings and preventing messy leaks that can become a real problem in your home.

Make Sure the Fitting Is in a Stationary Spot

Plastic compression fittings wear out even faster if they are in a location where they are moved often. These spots include the back of the refrigerator and on a movable dishwasher that is run up to the kitchen sink. The refrigerator tubing can cause rotation strain on the compression fitting, causing a slow leak that you may be unaware of until suddenly a shallow puddle runs out from under the fridge. Dishwashers can experience the same problem. Solve these issues by building your dishwasher into the cabinetry with a permanent water connection, and your refrigerator by clamping the copper coolant tubing to the back of the fridge.

Lubricate Compression Fittings before Reuse

The compression fitting for your refrigerator's icemaker, for example was only designed to be installed once. If it is in good shape and you want to reuse it after replacing a tube, lubricate the threads on the nut and the ring to get a good seal. Otherwise, replace the entire fitting. If an old compression fitting starts leaking, you can adjust it. Loosen off the compression nut by 1 turn, lubricate the nut and ring, then retighten it just 1/4 turn beyond the original snug position.

Lubricate New Plastic Compression Fittings when You First Install Them

Put a waterproof lubricant on all parts of the compression fitting when you first install it to help it maintain its seal longer.

Avoid Overtightening Plastic Compression Fittings

Compression nuts should only be tightened until you feel resistance when you turn it. They will crack plastic pipe, causing leaks, if they are overtightened.

Don't Use Metal Compression Rings on Plastic Pipes

Connect all plastic pipes and tubing with plastic compression fittings. Metal compression rings will crimp plastic pipe, causing instant splits and leaks. Take your plastic pipe to the building supply center and purchase a plastic compression fitting before installing the pipe.

Form a Snug Connection Between Pipe and Fitting Before Tightening

One of the main reasons why plastic compression fittings will not form a tight seal is that the pipe does not get seated deeply enough into the fitting. Insert the pipe and work it in until only about 1/8 inch of the pipe shows beyond the compression ring. Then you can tighten to the correct tension without worrying about cracking the pipe or tube.

If You Must Bend the Pipe

If you have to bend the pipe around an obstacle, leave the last 2 to 3 inches of it closest to the compression fitting attachment point straight. Plastic compression fittings cannot form a tight, leakproof seal on a bent pipe.