I just got a new hot water heater from Sears and it came with (2) nipples that I have never seen before. The nipples are 3/4" and are silver, may be galvenized? They have a blue plastic type of insert in them with one end open and the other end having 2 flappers. They appear to be NPT thread. Also, the cold water inlet has a blue colored something in the inlet.

What are these pieces for? Do I need to install the nipples or can/should I install the supply lines with out these nipples? Can I install the copper sweated male ends that can be gotten at the local home improvement store? Should these special nipples be installed on both the cold supply and hot outlet side of the heater? Do I need to remove the blue thing from the cold water inlet of the new heater?

Thank you for all of your help.

Don

These two nipples are called heat traps, when water is heated it expands and rises. These little flaps are to hold some of the heat in the water heater. You should use both of them. If you use copper pipe with solder joints you want to make sure and solder the 3/4 female adapter to a length of pipe and then let it cool before you screw it on to the silver nipples. Do not solder any fittings close to the nipples without using some kind of heat sink, a wet rag wrapped around the nipples will do the job.
The blue thing in the cold water side of the heater is called a "dip tube" it is there to carry the cold water entering the heater to the bottom of the heater and not mix at the top of the heater with the water that has already been heated.

Thank you sooooo much. I really appreciate it a ton.

I would hold out for an answer from Tom. Those fittings sound more like dielectrical unions meant to avoid electrolysis between the copper lines and the iron of the tank. Do they have a groove around the outside? I have a little problem understanding how they would do much good. If I remember correctly, Tom says you don't need them. If Tom says you don't need them, you don't need them. While you are waiting for him, try a search here on "dielectrical unions".

The one bit of good advice was the plastic in the inlet. It does run the incoming cold water to the bottom of the tank allowing the hot to come out the top with less mixing.

Letmetellu is correct. The nipples provided with your water heater are heat saving nipples. The flappers you see are meant to prevent some heat loss from your tank and increase it's energy efficiency.

If you are connecting the heater with flexible water heater connectors, I would suggest using a regular 3/4" brass nipple 4" or 5" long. Remember, the longer the nipple, the easier it will be to tighten and to work on down the road. Local plumbing inspectors have reported instances where the rubber gasket in the flexible connector losing seal with the plastic inserts in the heat saver nipples. If your using copper female adaptors for your connection, they should pose no problem.

We have had quite a few complaints on this page with heat saving nipples loading up with minerals and choking the flow of hot water. As a rule we solder a 3/4" male adapter on a 6" piece of copper and let it cool before we install them on the heaters in and out let openings. I would not suggest using heat trap nipples in a high mineral area. Regards, Tom

We do not have any problem with sedament in our area but I am not sure about the mineral content. I am going to install them and if there is a problem down the road I will take them out.

This water heater is used for the utility areas of the house. The washing machine, kitchen, 1/2 bath and 1 full guest bath. We have a tankless heater for the master bath, the "not living at home" kid's bath and 3rd bath.

Thanks again. Your help is priceless.

VULCAN water heater continuos model number 23001ono. I'm looking for a brass nut that sits on with a very small hole, with a number on it (25) PILOT LIGHT
My email [email protected]

And what's this brass nuts function? Back to you. Tom

Hello Tom,

Can you give him a new thread that other experts will see it, he responded to more than five years old thread, Thanks.

John