When looking to install a new hot water heater You will have to first perform the vent test. This is to see if your vents are properly directing airflow for the hot water heater. Close all windows and door. Turn on all the gas appliances and exhaust fans, turn the temperature of the water heater on for a few minutes, then place an extinguished match near the hood of the hot water heater. It should such in the smoke from the extinguished match. If it blows the smoke back, you have a venting problem and need to call a professional that works on hot water heater installation.
Next check the water pressure with a pressure gauge on your outside hose. 60 or 50 PSI is the ideal water pressure range. If it is higher, you can reduce it with a pressure reducing valve installed after the main water shut off.
Remove the Old Hot Water Heater
turn off the gas and use a wrench to disconnect the gas pipe from the control valve, then detach the venting from the top of the hot water heater.
Turn of the hot water from a faucet and let it run until the water is cool. Then, shut off the cold water supply to the hot water heater and connect a garden hose to the drain valve. Open the valve and empty the water from the hot water heater in the buckets or to a drain.
When the hot water heater tank is empty, remove the discharge pipe from the temperature and pressure relief valve, also called the TMP valve. Also disconnect the water pipes. If you have to cut them, leave them as long, in length, as possible. Then, remove the hot water heater itself.
To install the new hot water heater
Set the hot water heater in a drain pan and to avoid flooding, route it to a drain.
Install the drain pipe on the TMP valve. This valve opens when temperature and pressure are too high. If you don’t have a drain, place a bucket under the discharge pipe. Drain pipe should be no more than 6 inches above the bucket.
Use a flexible hose kit to hook up the water. (Universal Gas Water Heater Installation Kit). Make sure your kit also has a gas hose.
Apply plumbers tape on the threads of the key trap nipples and attach the hoses.
Remove the aerator from the faucet and turn on the hot water side. then turn on the cold water supply to the hot water heater.
Check your connection for leaks. If everything is good, continue filling the hot water heater tank. When water runs from the faucet then the hot water heater is full. Let it run for 3 more minutes to make sure water is emptied from the water heater tank.
Secure the venting to the new exhaust hood on the new water heater.
Connecting the gas line to the new water heater
To connect the gas line, first make sure the hot water heater tank control is off. Wrap the threads of the fitting with gas plumbers tap. Insert the flare nut into the control valve and screw the other flare nut into the gas line. Then connect the hose. Turn the gas line on and use leak detection solution to check for gas leaks. It will bubble if there is a leak. Tighten down the flare nut to stop the leaks.
Lighting the pilot to the hot water heater
To light the pilot, turn the button to “Pilot” then press the button and then press the “ignite” button. The light should blink when the pilot light is lit. 120 Degrees Fahrenheit is the recommended temperature setting.
You are finished installing your new water heater. But try the vent test again and call a professional if there is a problem.