A Four-Step General Approach to Replacing a Gas Water Heater
The hot water system installed in your home is designed to meet your household demand for hot water, but like other busy appliances in the home, it won't last forever. If yours is almost reaching the end of its lifespan, you should start planning for its replacement before it gives out.
If your existing water heater is gas-powered, it is likely that you're going to replace it with a unit of the same fuel source. However, you'll want to make sure the new water heater is the most efficient model that is large enough to meet your domestic demand for hot water.
Here are the 4 basic steps involved in removing an old gas water heater and installing a new one.
Step 1: Shut Off the Water and Gas Supply
The first thing to do is to turn off the water supply to the water heater. This can be done by turning off the cold water shut-off valve located above the water heater or shutting off the water at the main shut-off valve for the entire house.
Next, shut off the gas supply with the shut-off valve on the water heater itself.
Step 2: Drain the Water Heater Tank
Connect a garden hose to the drain valve located at the bottom of the water heater tank, and then turn on a nearby hot water faucet in the house to prevent suction in the lines, which can prevent the tank from draining completely.
Run the other end of the hose outdoors or over a floor drain. Open the drain valve slowly and let the tank drain completely. Close the valve and detach the hose.
Step 3: Disconnect the Water Heater
Disconnect the gas line to the old unit and the hot and cold water lines from it. You may need to use a tubing cutter, such as a pipe wrench, to disconnect the pipes. The water heater can be heavy, so you may need an extra pair of hands to remove it safely and properly.
Step 4: Install the New Unit
Put the new hot water unit in place and install the various fittings that come with it. Reconnect the hot and cold water pipes. Check if the nearest hot water faucet is still open before turning on the water supply. This will help prevent air from flowing into the hot water system and creating suction in the water lines.
Turn on the water for a minute or so before turning it off again. Reconnect the gas pipes, turn on the gas supply and wait to see if the water will heat up.
All hot water system changeovers must conform to the local plumbing codes, so make sure you know the applicable requirements for water heater replacement in your area. The above guide only shows the basics involved in the general process for replacing a gas water heater. It may or may not work for you depending on your situation. Contact a hot water system plumbing specialist near you to remove the guesswork out of the job.