How to Install or Replace a Tank Style Water Heater

Make sure you pull any required state or city permits for installing or replacing a water heater. Each city is different, and may require fees to pull a permit. If this seems overwhelming, call a license plumber like Reliant Plumbing! Whether you are in Austin, San Antonio, Westlake, Cedar Park or Round Rock, we can repair or replace hybrid water heaters.

It has helpful information for when you purchase a new unit, like energy specifications and size.

• Shut all doors and windows. 
• Turn on all exhaust fans and gas appliances.
• Turn up the tank temperature for a few minutes.
• Hold a just-extinguished match near the vent hood.
  • The hood should pull in the smoke. If the smoke blows back toward you, you have a venting issue and should call an expert for repairs.

Use a pressure gauge on your outdoor spigot to check your home’s water pressure. The ideal range is 50 to 60 psi.

• If the reading is higher than 80 psi, use the pressure-reducing valve installed after the main water shutoff to lower it.
• You should consider getting an inline pressure gauge and a thermal expansion tank. An expansion tank helps get rid of excess pressure in the lines.
  • You can use push-fit fittings to easily install an expansion tank.They easily slide under the pipe without the need for soldering.
  • The expansion tank pressure should match the main water pressure. You can depress the valve to lower it, or use a hand air pump to increase it.

• Turn off the gas, and disconnect the gas pipe from the control valve with a wrench. 
• Detach the venting. 
• Open a faucet on the hot water side. Let the water run until it’s cool. 
• Turn off the cold water supply.
• Connect a garden hose to the drain valve.
• Empty the tank into a drain or buckets after you open the valve. 
  • To drain the tank faster, open a hot water faucet.
• After the tank has emptied, remove the discharge pipe from the temperature and pressure relief valve (T&P relief valve). 
• Disconnect your water supply pipes. 
  • If you must cut them, leave them as long as possible. 
• Remove the old tank.

Place the new water heater in a drain pan & route it to a drain or the exterior of your home to avoid flooding.

When pressure and temperature are too high, this valve opens. 

If you don’t have a floor drain, put a bucket underneath the discharge pipe. The pipe should be no more than 6 inches above the bucket. 

You can easily connect the water with a flexible hose kit.

Check that your kit also has a gas hose. 

• Put plumber’s tape on the threads of the heat trap nipples. Attach hoses.
  • To reduce corrosion between two different metals, some areas may need dielectric fittings. 
• Put plumber’s tape on the connector body threads.
• Securely connect the body threads to the hose. 
  • Hold the hose up to the pipe. There should be a little slack.
  • Mark the pipe, and then cut it. 
  • Deburr the pipe.  
  • Slide the compression nut onto the pipe. 
  • Place the pipe into the fitting. 
  • Tighten the nut.

• Open the hot water side of the nearest faucet, after removing the aerator.
• Turn on the cold water supply at the water heater. Check for leaks around the water heater.
• If everything looks good, continue letting the tank fill. You can tell the tank is full when water runs from the faucet.
• Allow the water to run from the faucet for about 3 minutes to empty air from the tank.

Attach the existing venting to the new exhaust hood. If you do not have existing venting, you’ll need to vent your gas water heater through your roof. We recommend calling a licensed plumber for proper venting.

• Make sure the tank’s control knob is turned off.
• Wrap gas plumber’s tape around the threads of the fittings. 
• Insert a flare nut into the control valve. 
• Screw the other flare nut into the gas line. 
• Connect the hose. 

Turn on the gas supply. Check for leaks with leak detection solution. 

• If you have a leak, the solution will bubble.
• If needed, tighten the connections.

To light the water heater pilot, turn the control knob to pilot and push the igniter button. When it’s lit, the light will blink.

The recommended temperature setting is 120 degrees Fahrenheit, but you may want it hotter or cooler depending on your personal preference. Test the temperature of the water at a faucet and then adjust the temperature on the thermostat.

Repeat the same vent test steps as above.  If there’s a problem, call an expert to assess the issue.

After waiting a few hours, examine the discharge pipe. 

• If the pipe drips, that usually indicates that the pressure is too high. Adjust the pressure to under 80 psi.

Sometimes faucets have reduced flow after replacing a water heater due to sediment trapped in the line. If this happens, just remove your aerator and flush out the sediment before replacing it.