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Post Info TOPIC: Replacing a Water Heater


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Replacing a Water Heater

If you have a gas heater now,, it should be a easy change over,, first of all you need to get the new one out of the box,biggrin the box will make a neat tunnel for your kids to crawl through,wink
set the new one up close by the old one,, so you can compare the hookups. Cold water in , hot water out.. should be marked on the outlets where the pipes enter the top of the heater, H and C,, if the new one is close to the same size ,, you can probably reuse the pipes and union connecters, also tyhe gas connections ,,, if you can take a few pictures and post them,, it would probably be easier to explain it all to you,, especally if there is a differance in heaters,, but most are pretty much the same except for height,, the new one might be a little taller if you got one with more gallons capacity, The first thing to do is Be SURE you DRAIN the water out of the old one, a garden hose will fit the fitting at the bottom of the heater

As for tools,, you should just need a couple of 8 or 10" pipe wrenches,, and maybe a 10" cresent wrench,,
just watch how the old one is hooked up and replace the new one in reverse order,,

Post some pictures if you can You can do it Dude,, I know you can,, weirdface

This might help

Replacing a Water Heater


One of the most common household plumbing projects is replacing a water heater. Many potential dangers can result from improper water heater installation. Be sure to check your local codes. Use only the procedures and materials your code allows. This booklet covers replacement of natural gas, LP gas and electric water heaters, the most common types.


  • The most common overhead-plumbed water heater hookup is shown. Before your can connect the new heater, the old one must be removed.

  • First, turn off the gas or electricity to the heater.

  • Next, drain the heater. Open a hot water faucet to allow air into the system.

  • On a gas heater, separate the vent pipe from the draft hood. The hood should lift off after you remove the sheet metal screw that holds it. After checking that the pilot light is out, disconnect the gas line at the heater and cap it.

  • Next, remove the heater from its water piping. If the pipes are connected with unionsremovable threaded fittingstake them apart with a pair of pipe wrenches. Pipes without unions must be hack-sawed off. A pipe/tubing cutter will also do the job. The old heater can now be removed and disposed of in an approved manner.


You need the Flash plug-in to view animations. Click to install Flash.

The most common overhead-plumbed gas water heater hookup. you must comply with all applicable codes.

Connect a garden hose to the drain valve of your old heater and run it outdoors or to a drain.

For pipes not connected with unions, saw off the riser pipes above the heater.


  • Move your new heater to its location by "walking" it or by using an appliance cart, dolly, or hand truck.

  • Position the new heater so your pipingparticularly a gas vent pipewill reach easily.

  • For a gas heater, install the heater's new draft hood. Many heaters have legs that insert into holes on the heater's top. Every gas water heater needs proper venting that's no smaller than the draft hood collar of the new heater. It's a good idea to use new vent pipe elbows, since the old ones are probably corroded at their present angles. The vent should go straight up as far as possible. Any horizontal run in the vent should slope upward at least 1/4" per foot, as shown. Connect the vent pipe with short sheet metal screws.

  • Now you can make the hot and cold water connections. The type of materials you use will depend on your local code and the type of material used in the existing system. One of the easiest ways to make these connections is using flex-connectors. Flex-connectors are easy to bend to reach the connection.

  • The water piping is handled depending on whether your house has threaded metal, sweat-soldered copper, or thermoplastic piping, and whether the piping is 3/4" or 1/2". Whatever the piping, the heater should be fitted with a cold water gate valve. Place the valve in a vertical section of piping to keep it from becoming fouled with sediment.

  • For threaded pipe, you should have a union on both the hot and cold water lines. Old unions should be replaced. The two halves of a union are manufactured to fit together properly; replace the entire union. You will need new nipples for the top of the water heater. Their length will depend on the distance from the fittings on the top of the water heater to the unions. Allow for the distance the pipe threads into the fittings.

  • Unions are not necessary with flex-connectors. Use PTFE tape (but not pipe dope) on the male threads entering the flex-connectors. If your water heater has female-threaded tappings, you'll need a pair of 3/4" nipples to accept the flex-connectors at the bottom. If the heater comes with 3/4" male-threaded stubs, the nipples are not needed. At the top, the flex-connectors fit directly to the ends of the threaded pipes (or a male adapter for converting to copper or plastic). Some flex-connectors install to copper tubing without sweat-soldering. If you sweat-solder, be sure to do this before installing the flex-connectors to avoid damage to the connector gaskets. Unions are usually not needed with flex-connectors.

  • Thermoplastic pipe. Flex-connectors are not necessary with CPVC or PB plastic pipe. You'll need "transition unions" between the metal heater threads and the plastic piping. Some plastic fitting manufacturers also call for using foot-long threaded steel nipples between the water heater and the transition unions to distance the unions from conducted burner heat. You can use rigid CPVC tubing, solvent welding the joints. Or you can use flexible PB pipe, joining the joints with mechanical couplings. PB cannot be solvent welded. Don't try to hook up a water heater with PVC, PE or ABS plastic piping, since these will not take hot water. \

Legs of the draft hood slip into holes on top of the heater.

Horizontal runs of vent pipe should slope upward at least 1/4 inch per foot to properly vent gases.

Use one sheet metal screw to secure each vent pipe joint and the joint with the draft hood.

Unions and gate valves make water heater installations and maintenance much easier.

Click on drawing above to view animation.

Flexible PB tube may be used to connect a water heater. Be sure to install transition unions and the proper adapters.


  • A vital part of your water heater installation is a temperature and pressure relief valve and relief line. The relief system lets off excess heat and pressure automatically.

  • With all the plumbing connected, you can close the heater's drain valve and open the cold water inlet valve to fill the storage tank. Open a hot water faucet to release trapped air in the top of the tank. Close the faucet soon since water flows readily from it. Be sure to check for leaks.

Always install a new temperature and pressure relief valve in your water heater.


  • The last step in completing the installation is to connect the gas or electric lines to your heater.

  • Gas connections. If there was no shut-off valve on the gas line before, add one. A new union should be used to complete the gas line installation with threaded pipe. For flex-connectors, install a male flare adapter into the inlet opening of the heater's gas valve. Connect the gas flex-connector collar to the flare adapter (no dope or tape), and tighten it with an adjustable open-end wrench. If everything is ready, see that the thermostat is in the off position. Then you can turn the gas on.

  • Electrical connections. The wires serving an electric water heater must be the right size, providing the proper voltage and amperage your heater is designed for. Hire a qualified electrician to wire the heater, unless you know how to work with such wiring. When you turn the heater circuit on, check the electric meter to see that it is spinning. This indicates that the heater is working.


  • Water that's draining from a heater may be quite hot, so use care.

  • When sweat-soldering copper tubing, be careful not to start a fire. Wet any wood that is nearby. Use metal shielding. Make sure that no gas is leaking. Have a fire extinguisher on hand.

  • The cold water gate valve must be left open while a water heater is in use.

  • Check the relief valve periodically to make sure it opens and then closes again. Remember that water coming from the relief pipe may be very hot. The relief line shown in Fig. 1 is a safety feature. It directs any hot water the relief valve releases toward the floor. They are required by most local codes.



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