Gas hot water heater Installation
Apply gas-rated pipe thread sealant or tape (don't use standard white Teflon tape) to the gas nipple and thread it into the new gas control valve. Tighten the nipple using two pipe wrenches (Photo 7). Assemble the tee and drip leg using the same two-wrench technique.
If the old section of pipe below the union no longer fits, you'll need to measure for a new nipple (Photo 8). Make sure you assemble and tighten the gas union before you measure the length for the intermediate nipple. Add 3/4 in. to 1 in. to this measurement and buy a new nipple. When the gas connections are complete, turn on the gas and check for leaks (Photo 9). You can buy leak detector in a convenient spray bottle ($3) or mix your own solution (one part dish detergent, two parts water).
Open the water valves and an upstairs faucet and fill the tank. Leave the faucet open until water flows out. Then shut it off and check the new water connections for leaks. Open the gas valve and light the pilot light following the manufacturer's instructions. You're in for a pleasant surprise with your new water heater—manufacturers have done away with the old “match-lit” pilot system. Instead of igniting the pilot with a match or lighter, you just push a button.
When the burner fires up, test for “backdrafting, ” which can allow deadly carbon monoxide into your home. Close all doors and windows and turn on kitchen and bath exhaust fans. When the burner has been running for at least one minute, move an incense stick around the draft hood. The smoke should be drawn up into the vent. If not, the exhaust may be entering your home. Turn off the gas and call in a professional plumber.
Finally, set the thermostat to a safe temperature. (For help, search for “water heater temperature” above.) In about two hours, you'll have enough hot water for a well-deserved long shower.
Old Gas Valves Can Leak
The “grease-pack” valves found in older homes tend to leak as they age. Even if your local code doesn't require replacement, we recommend you install a ball-type gas valve instead ($10). Replacement isn't difficult; you just unscrew the old valve and screw on the new one. But you will have to turn off the main gas valve and later relight pilot lights. If you don't know how to handle these tasks, call in a professional plumber and expect to pay $80 to $150.Replace old grease-pack valves with new
generation ball valves.
Local Code Requirements
You'll find lots of accessories for your new water heater at the home center. Some are required by local codes; others are just good ideas. Plumbing codes vary, so check with your local inspector.
1. Gas shutoff valve
All codes require a gas valve near the water heater. If you have a “grease-pack” valve, see "Old Gas Valves Can Leak" section above.