How To Install a Water Heater

Installing a new water heater yourself vs. hiring it done will  save you a ton of money —  roughly a thousand dollars, possibly more.  I recently received an estimate to install a new water heater in an apartment I own, the price was $1,800.00 ( Water Heater + Installation!)

Top of the line water heaters of the 50-60 gallon capacity, cost roughly $550-$650.00. That means the installation is about $1,200.00. Whew, that’s a chunk of change! Installing a new water heater is really quite simple. On the surface, the task might seem overwhelming or outside the realm of your ability, but once you learn how truly simple it is,  you will wonder why you have not done it yourself in the past.


Broken water heater
Ranger and I decided this water heater needs to be replaced.

Determining When To Replace Your Water Heater

More often then not, your water heater will tell you when its time to replace it. The following are just a few simple things to look for when determining when replacement is necessary:

  • Pilot Light has gone out- Looking through the small glass window or by removing the outer cover plate at the base of the water heater, determine whether the pilot light has gone out. ( The pilot light is a small blue and yellowish flame that is usually less then 1″ tall). Often times a draft of air or a temporary disruption in gas flow can cause the pilot light to go out.
  • Air Drafts or Gas flow disruption- If there are no obvious signs of problems ( such as flooding), try relighting your water heater following the instructions on the water heater that should be present on the water heater itself. In most cases this process involves turning the control knob to the off position, waiting several minutes to ensure any pockets of built up gas are dissipated, turning the control knob to the “pilot” position and depressing the igniter button (sometimes repeatedly, until the pilot light begins to burn) Then, after approximately 1-2 minutes of depressing the pilot button, releasing the pilot button and turning to the on position. The pilot light should remain on.
  • Sediment build-up – Over time, your water heater will build up sediment inside the water tank. The rate at which this happens is commonly determined by the type and amount of minerals contained within the water in the area in which you live. Sediment buildup will cause your water heater to operate less efficiently and also will reduce the amount of hot water contained within the water heater itself. The reduction of hot water can certainly cause issues especially in a multi person household. If this is your situation, then consider replacing your water heater right away as it will only be a short period of time before the heater goes out completely.
  • Rusting and Leaking- The obvious sign that your water heater needs replacing is the hot water stops flowing and upon investigation you discover that the utility closet is flooded and the clear source is the water heater. Hopefully there is a water heater pan and/or there is a drain very near by.


How To Install A  Gas Water Heater

Some Very Basic Tools is all that will be required

Tools Needed;

You can purchase the necessary tools on Amazon above.

Locate the gas line shut off valve and turn it off. Usually a half turn counter-clockwise


Locate the water shut off valve and turn to the off position


Loosen the Drain Valve at the bottom of the Water Heater to out let all the water that may be remaining in the tank.

Water Heaters are very heavy even without water in them. At 8 lbs a gallon, water in a 50 gallon tank can weigh as much as 400 lbs. Make sure you drain as much of the water off as possible, I like to lay the water heater down following disconnection to drain any excess water out the top whenever possible to lighten the heater as much as I can. Use a Hand Truck or Dolly with a strap when moving the old & new water heaters and always have two people present when moving the water heater.


Loosen and remove the old water supply lines. There will be 2 lines, a cold in and a hot out


Notice all the corrosion buildup, it is a good idea to install all new supply lines when replacing a water heater. I also replace the gas supply line with the new installation.


Using the Channel Lock Pliers and a Crescent Wrench, Ranger and I disconnect the old gas supply line. 2 Crescent Wrenches could also be used here.


Finally, remove the venting on the top of the water heater by removing the screws. Typically, there are 3 screws surrounding the water heater vent.

A quick review;

  • Turn off the gas at the  supply line valve.
  • Turn off the water supply line valve.
  • Loosen the water drain valve at the bottom of the water heater.
  • Remove the gas supply line at the water heater.
  • Remove the 2 water lines at the top of the water heater.
  • Remove the venting at the top of the water heater.

The water heater is now disconnected and may be removed from its position. Tip the water heater over on its side to drain all water out if the area permits it, (floor drain). Have a Hand Truck and a buddy help you to remove the water heater and to move the new water heater into position.

Purchase a Hand Truck or Dolly Here on Amazon (Link To Amazon Hand Trucks)


Hooking Up The New Water Heater

We need to make sure that the water heater we purchase is going to fit the area in which the installation will occur. Using the tape measure, measure the height of the old water heater. It needs to be close enough in height to ensure it will not only fit the space but also hook into the existing gas and water lines. As mentioned earlier, I always replace the old connection hoses, just make sure you purchase a length that will easily make the new connection. Check the old water heater for gallon capacity, and measure the circumference of the tank to ensure the new one will fit the installation location.

Remove the new Water Heater from the packaging and place it in the correct position for hook up


Installing the new Water Heater is essentially as easy as removing the old one…just everything in reverse.

Wrapping the gas line threads with plumbers tape
Make sure there are no kinks in the line as you complete the Installation of the new Gas line connection hose.


Plumbers tape on the threads, no kinks in the line as you snugly tighten the water supply lines. Make sure that you connect the water line in to the inlet bib marked “Cold” and the line out to the bib marked “Hot”


Secure the new venting on the top of the water heater. In this case, the existing venting was in good condition and I chose not to replace it. Make sure that it good and secure and that the venting itself does not contain holes and is not kinked. I like to light a wooden match at the base of the vent to ensure that it is drawing or venting properly.

Turn the main water valve on and begin to fill the new water heater, check for leaks in all your connections as the tank fills. Turn the gas valve to the on position.

Remove the panel below or near the control panel. Follow the lighting instructions that will be posted at or near the control panel.
Once the water tank has filled, and the pilot light is on, check for any leaking gas by applying a soapy water solution to all the connection points for any gas line hook up connections. If any type of bubbling occurs in the solution it means that you have some leaking gas. Turn off the gas supply immediately and reconnect your gas connections. Repeat this process until no bubbling occurs, ensuring a safe connection. (Diluted dish soap work quite well for this testing process)


Adjust the temperature setting on the Water Heater control knob for your desired water temperature. Make sure that the temperature is not set so high that it is scalding as it comes out of the faucet, this can cause serious burns. My preferred setting is at a medium high level, choose your own preference but choose it carefully and wisely.