HOW TO REPLACE A HOT WATER HEATER
New Hot Water Heater
Unions (possibly if needed)
Hack Saw (possibly if installing new pipe unions)
Pressure Relief Valve ( Possibly if the old one is hard to operate manually after trying)
There comes a time when every water heater reaches the end of it's life. Our present water heater was installed ten years ago. It still works.
The usual cause for failure of a hot water heater is when the tank develops a pinhole leak. When you see drips or a puddle of water under the heater, its time for a new heater. You can replace the heater with a bigger capacity heater if you want to. This may be required if you find yourself running out of hot water when several people shower or take baths.
Its always easier to do this replacement if you have a friend there to help you move around the bulky heater. But, it can easily be a one person job. Either way, don't be afraid of this job. Its not as hard as you might think.
Keep in mind that a hot water heater is always full of water. FEMA suggests keeping a gallon of water per person per day on hand. If you have a 40 gallon tank, then you have a built in 40 gallon supply of drinking water for use in an emergency.
1. Before you take out the old water heater, you must turn off the water and turn off the fuel or electric power supply. Disconnect the gas line or electric lines. Your old heater probably has unions which connect the individual hot and cold pipes to the heater. If you aren't lucky enough to have unions, then saw the supply pipes, remove the pipe stubs, and replace with new threaded pipes connecting to the unions when you reconnect the water supply.
2. The heater has a temperature pressure relief valve on the top. It looks like a metal flip switch. If that valve still works, the reuse it. If it doesn't easily flip open and closed, then replace it with another one. Just flip it once or twice to make sure the old one still works.
You need to drain the heater tank then. The heater tank has a drain valve spigot at the bottom. Connect a water hose to the spigot and drain the tank into a bucket or a drain. Control the flow as needed by the spigot.
3. Disconnect and lift the exhaust vent flue pipe, if there is one, off of the heater. Electric heaters don't have one.
4. Tilt the empty tank over and carry it outside with a friend's assistance.
Place the new heater in position where the old heater was located. If you have decided to replace the old heater with a bigger capacity one, now is the time to make whatever length adjustments are needed in the water supply lines.
5. Coat the inside of the union joints lightly with plumber's putty and attach the water lines to the unions and to the heater.
6. The heater then needs to be connected to the exhaust gas vent flue pipe if it is a gas heater. A draft regulator is placed on the top of the heater next. It comes with the new heater. It's a cap with open bottom sides and an open top that you will place on the top of the heater. You then reset and attach the exhaust pipe snugly on the exhaust vent flue pipe. This exhaust gas pipe must be held in place to the draft regulator with sheet metal screws.
7. The new water heater must be filled completely with water before it is lit. Do not under any circumstances light the heater or switch on electricity to he heater if it is not full of water.
8. Fill the tank in the following manner. Open a hot water faucet at a sink, turn on the water supply to the heater, and wait until cold water comes out of the hot water faucet. When cold water comes out in a good flowing steady stream, then the tank is full. Close the faucet, and power up the heater.
9. Folow the instructions that come with the water heater to light the pilot light on a gas model or power up an electric water heater.
10. Once you have initially filled the new heater, then the tank automatically refills through a tube and goes to the bottom of the tank for the water to be heated.
10. The heater has a thermostat to control the temperature of the hot water. It has a range of about 120 degrees to 180 degrees, which is enough to scald at the higher settings. Start with the temperature on the low side, which is no higher than 130-140 degrees. You can always adjust slightly upward if the water isn't warm enough for you. Don't adjust the water heater heat too high.