If your hot water tank is older and you don't regularly drain and refill it, draining it may actually create an irreparable leak.
Step 1 Test the water Feel the water. If you turn on a hot water tap and the water is cold, or if you expect to climb into a nice, hot shower and are blindsided by icy water, it's probably time to replace your hot water tank.
Step 2 Check hot water duration See how long your supply of hot water lasts. If you used to take much longer showers before the hot water ran out, there is probably a problem with the tank. You may need a new one.
Step 3 Look for puddles Check the floor around your hot water tank for standing water. If there are puddles or pools of water around the base of the tank or a stream of water running from the tank to a floor drain, there may be a major enough leak that you will need a replacement.
Step 4 Check for smaller leaks Inspect the fittings and plumbing connections. If there is water, sludge, or corrosion, there is likely a leak, and it may be time to get a new tank.
Step 5 Listen to it Listen to your hot water heater. If it frequently makes clanging noises, or if you hear pops or other unusual sounds, there is probably a mechanical problem. You will need a replacement tank.
Step 6 Check the tank's age Check the age of your hot water tank. Most hot water tanks are warrantied for 5 to 10 years. While many last for years beyond the warranty's expiration, if you notice inadequacies in your tank's performance and the tank is beyond its warranty date, it's probably time to get a new one.