If your water heater has a broken dip tube the most common symptom is luke warm water when you're expecting hot. But depending upon where the dip tube breaks, you may simply find that your water isn't as warm as it used to be. A dip tube is a long plastic tube that runs within your tank. It starts at the cold water inlet and extends all the way to the bottom of the water heater. The water enters the water heater at the top, however it's heated at the bottom of the tank. The dip tube carries the water from the top of the heater to the bottom where it'll be heated. As cold water enters the tank, the heated water rises to the top and is drawn thru the hot water outlet.When hot water is drawn from the tank, it is replaced with cold water. To prevent the cold water from cooling the ready-to-use hot water, the dip tube delivers it to the bottom of the tank. Over time, a dip tube will crack, develop mineral deposits, or even break entirely. When this happens, the cold water enters the tank at the top and mixes with the hot water since the tube will abruptly end somewhere above the bottom of the tank. The result is lukewarm water. Necessary SuppliesWrenchCopper Pipe Cutter (if you have copper pipes leading into your cold water inlet)Dip TubeTeflon Tape How to Change a Dip Tube Step One - Turn Off the PowerTurn off the power to your water heater. With an electric water heater turn off the breaker at the electrical panel. On a gas water heater, set the dial on the gas regulator to off or pilot.Step Two - Turn Off the WaterClose the valve on the incoming water line to the water heater. There is generally either a dial or a lever that you can use to turn off the incoming water. In some cases, water heaters are installed without a shut-off, if this is your situation you'll need to turn off the water to your home. We highly recommend installing a shut off valve.Step Three - Drain a Few Gallons of WaterAttach a garden hose to the drain valve and open a hot water tap in the house. Allow a few gallons of water to drain from the tank.It isn't necessary to drain the entire tank, but draining a few gallons will clear any water that may be in the hot water pipes above the level of the top of the tank. Step Four - Disconnect the Incoming Water LineFlexible Hose Connectors - If your water heater is connected to the incoming water line with flexible hoses you'll be able to simply use a wrench to disconnect the hose from the cold water inlet nipple. Copper Pipes - If your water heater has a copper pipe connecting it to the incoming water line the task is a bit more complicated. You'll need to use a pipe cutter to cut the copper pipe between the cold water shut off valve and the cold water inlet nipple on the water heater. Step Five - Remove the Dip TubeUse a wrench to unscrew the incoming water nipple, and gently pull the dip tube from the tank. Remember, the dip tube may be fractured, corroded, or completely broken off. Try not to touch the sides of the water heater with the dip tube as you are removing it as this could cause it to break and fall into your tank. If the dip tube is in good shape, there may be another problem, such as a heating element or thermostat. Step Six - Install the New Dip TubeWrap the treads of the new dip tube with Teflon tape and insert it into the tank and secure it in place. Connect the plumbing to the water heater. If you have copper pipes you'll need to solder them back together. Step Seven - Turn on the Water and PowerOpen the cold water supply valve and allow the tank to fill. Be sure the tank is completely filled before your turn the power back on. If the water level is below the upper heating element on an electric water heater they will "dry-fire" and burn out. Watch the VideoThis video will show you how to replace a dip tube on your water heater.