How to Repair a Leaking Hot Water Tank

A man adjusts a water tank.
  • 3 hours
  • Intermediate
  • 50
What You'll Need
Copper pipe cutter
Pipe threader
Dry cloths
Pipe wrenches or adjustable wrenches (2)
Teflon plumbers tape
Garden hose

After a few years, you may find that your hot water tank has begun to leak. A few steps will help you to resolve most of your leaky water heater tank problems.

Step 1 - Take Safety Precautions and Prepare

Make sure to turn off any electricity, breakers, and other power to your electric water heater. If you have a gas water heater turn off all gas and water valves. No smoking in the vicinity of a gas water heater, and make sure that you are not wearing any loose clothing. Wear rubberized gloves and rubber sole shoes if you have an electric heater to remove the risk of latent voltage in the system.

In addition to turning off gas or electricity you need to also turn off any water supply valves to the water heater, both the cold water inlet and the hot water exit pipes. Expel the water from the tank by hooking a hose to the outlet and draining into a floor drain or outside. Attach the hose to the sillcock valve that can be found on the bottom of the tank, and then open the valve.

Step 2 - Inspect Your Water Heater

Wipe up any water from the floor and from the fixtures around the water heater. After you have the fixtures dry you can trace the connections and the base of the water heater with your hand or eyes and determine where the water is leaking from.

Step 3 - Fix Leaky Pipe

Using the two wrenches, tighten the connector. If this does not resolve the leak, put a bucket under the pipe to catch any water and open the connection. Wrap Teflon tape around the male threaded end of the pipe tightly three times so the shape of the threads is evident, and then reconnect the two sides of the pipe. Turn the water back on and verify that the leak has been corrected.

Step 4 - Fix Leaky Water Valve

If water is leaking from a water valve, try tightening the connections using the two wrenches. It is important to use two wrenches to ensure that you have a proper grip. Tighten without damaging the pipes. If tightening the valve does not eliminate the leak then replace the water valve by removing the old valve, adding Teflon tape to the male end of the connector, wrapping it around three times and tightening the connections between the pipe and the valve.

Step 5 - Finish and Test

Make sure you have removed the garden hose and closed the sillcock. Starting with the hot water output valve, open all the valves and check for leaks. If you find that there is no more leaking of water from each of the fittings and valves you have successfully relieved your system from leaks. A hot water unit is a closed system that should never leak and should hold pressure to help water flow through your pipes and to your faucets. After you repair your leaks you will find improved water pressure.