What is the best way to connect water pipes to a water heater?

Question

Should the pipes have NPT adaptors at the end, and then use a flexible hose with NPT connectors at each end, to connect the pipe to the water heater? If that's the best way, what is the best way to put the NPT adaptors on the ends of the pipes?

Answer 1

If electric then flex is better since they don't last as long as gas heaters.I always use flex(It makes it much easier to change one out).

Answer 2

Yes, flex hose is the best and easiest way to connect the water heater. Putting NPT adapters on depends on the type of pipe you have. If the pipes are copper they will have to be soldered on. If they're PVC you glue them on and if they're the older galvanized variety you use a threading die to cut threads directly in to them so you can s***w the flex hoses on.

Answer 3

here's two scenarios assuming you have a gas heater:

using flex requires the water heater be earthquake strapped well.  the flex makes it easy to install but not as structurally sound.  

during a major earthquake here, all heaters plumbed in with old galvanized pipes stayed put while all water heaters plumbed in with flex walked away with broken water lines and gas lines.

plumbing in "hard" is more stable although it takes a little more time and may cost more.  the code requires earthquake strapping also so it is doubly rigid.

installing the proper fittings for either scenario can be done easily by a qualified person.  always be sure to check for proper venting when the job is done.  carbon monoxide is "the silent killer"...

ultimately,  it's your choice...  

Answer 4

The flex pipe is a great option as it allows some position flexibility. I have always used a compression fitting and adapter on the supply side and have never had one leak.

On a side note have you considered adding a 1/4 turn shut off valve to the lines just off the heater so that in the future if you need to do a plumbing repair inside the home or an outdoor spigot than turning the water off is a snap. the  

Answer 5

First of all if you need to install a copper or galvanized pipe nipple coming out of the water heater on both the hot and cold fittings. Next install a union on each line. Unions allow the easy disconnection of the water heater. If it is an electric water heater you need to use a " dielectric union on both lines". After the unions install a "ball valve" on just the cold water feed to the water heater. Now you can hook up your flex line.

*Usually water heaters come with 3/4" female pipe threads. So just start with 3/4" pipe nipples 8-10" long, then the 3/4" unions,then some shorter 3/4" pipe nipples 6-8" long, then a 3/4" shutoff valve on the cold.

On the hot you will hook your flex line right onto the 3/4" male threads of that last hot water nipple. Just explain to the clerk at the DIY center what you need as far as flex lines. Be sure to measure the distance from you incoming cold and outgoing hot lines to get the right length of flex line.

You'll need some pipe dope, 2 pipe wrenches - good luck.