Water Heater Issues - Troubleshooting A Decrease In Water Temperature

If you have a gas water heater, then you should know that the appliance is likely to last around 10 years before a replacement is needed. However, you may notice some issues in the way the appliance functions well before the 10-year mark. Specifically, if you notice warm instead of hot water coming out of your faucets, then there may be an issue with the way the dip tube is working. Keep reading if you want to understand what this part of the appliance is and how you can replace it if there is a need.

Understanding the Dip Tube

Gas water heaters work by allowing a burner at the very bottom of the tank to heat the water inside. A thermostat inside the tank tells the burner when to turn on, and this allows the water in the tank to remain at a constant temperature. When you turn your hot water faucet on, water leaves the tank through a pipe that sits on the top of the appliance. As water leaves, cold water enters the tank through an inlet pipe that extends from the top of the tank almost all the way to the bottom. The pipe that allows new water to come into the tank is called a dip tube.

The dip tube releases water at the bottom of the tank so it can be heated by the burner. Cold water is heavier and more dense than hot water, so it will remain at the bottom until it warms up. The hottest water in the tank moves to the very top of the tank where it will move through the outlet pipe sooner than the warm or cool water in the tank.

Dip Tube Issues

This entire water heating process stops working correctly when the dip tube breaks or forms a hole. This is common for some water heaters that contain weak PVC pipes. These pipes are constantly stressed by the 120 or 140 degree Fahrenheit temperatures inside the appliance. Once the dip tube breaks, cold water is allowed to mix with the hot water at the top of the tank. This creates lukewarm water that is then released out of the outlet pipe. Not only will the water be cooler, but small bits of the PVC dip tube may break away, enter the water lines, and clog your faucets.

Fixing the Issue

If your faucets are releasing warm water instead of hot water, then look to see if your thermostat is set correctly and also check to make sure the pilot light is lit. If these things check out, then look for a dial on the water heater and turn it to the "off" position. This will essentially turn the heater off and allow you to work with it safely. Allow the appliance to sit for two or three hours so the water can cool. Turn the valve to the "off" position on the water inlet pipe as well. 

Removing and Replacing the Tube

You will need to release the dip tube from the water inlet pipe. This means cutting the PVC pipe just underneath the shutoff valve. Use an adjustable, ratchet, or single-handed pipe cutter for the job. All three of these cutters are easy to work with. Once the pipe is cut, pull it out of the tank and look for cracks, holes, or other types of damage. If you see damage, then you have successfully found the source of the water heater difficulty. Use a plumbing wrench to release the rest of the dip tube from the cold water supply line.

You can purchase a new dip tube to replace the old one, or you can purchase a long piece of CPVC piping to replace the old PVC material. This material is ideal because it can withstand temperatures above 200 degrees Fahrenheit. Purchase a piece of CPVC that is the same length as your old dip tube. Make sure one end of the pipe is threaded so it can twist into the end of the cold water pipe. You also should think about wrapping a piece of Teflon tape around the threads before securing it in place to reduce leak concerns. 

You can also call a water heater service if you can't seem to correct the problem yourself.