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Tanklets > Heat Trap Issues

Shape and Stainless Vs. Copper

Q: I have used Corrugated copper tubing to make "S" bend heat traps before but now there seems to be a debate whether
corrugated stainless steel tubing is better. I know that if the copper develops a pinhole leak that it can be fixed but stainless steel must be replaced. What is the current thinking about this question, Also, is there an opinion on "S" bends versus loops for heat traps.

A: Hello: Regarding copper vs stainless, it really depends on your water quality. In my area I have seen copper connectors get pinhole leaks, but it's rare and takes many years. So, if you have frequent problems with copper, switch to stainless.

Stainless might not like softened water because of the higher salt content however, so I would stick with copper if you use softened water. Some benefits of stainless is it's greater flexibility and that it doesn't work harden like copper, so is easier to make work in tight places. With either type of flex connector, I like to make sure it has a true dielectric built into the ends. You can tell because you'll see a plastic ring between the nut and tubing, along with the rubber washer.

About heat traps, the shape of the trap doesn't really matter.  What does matter is the depth of the trap.  I like to get at least six inches of height in the "trap". With either type of connector, go back after it's been in place for six months and re-tighten the nuts.  The rubber washer can shrink, making the fitting loose. -- Larry (1/12/10)

Damaged Heat Traps

Q: I just replaced my water heater today with a new 50 gal. GE electric. It came with what appeared to be blue plugs in the nipples for the water lines. I then attempted to pull the plug out, then realized it was actually the heat trap valve. So, needless to say I knew it wouldn't seal right on my hose with that jacked up plastic sticking up, so the little bit that sticks up to form the seal on your hose, i cut it off flush with the top of the nipple. Hooked my hoses up and to my surprise it didnt leak. I am thinking that by cutting off the sealing part of the heat trap, i have more or less bypassed it.

Now my question is, the cold inlet line is now HOT, like hot enough to burn. It is about 20" from the nipple to the wall and it does get a little cooler as you get further from the heater. So, do I need to find and purchase another cold inlet nipple with the trap in it? Or can i rig up the flex hose and some copper somehow? Im just not comfortable knowing some of my hot water is expanding up into my cold line.

PS. No i didn't read the directions first, and yes my wife has explained the importance it. ( several times)

A: Hello: It's genetic. Guys don't read instructions or ask for directions... So, what you're experiencing now is partly thermal expansion and partly convection back up the line/s. Cutting away the plastic on the nipples exposed steel to water and it will rust. I don't know how fast. The nipples should be replaced at your leisure. Both hot and cold lines want insulation back to the wall. It comes as six foot long tubes, pre-slit down one side. Use 3/4" thick insulation as long as you're at it as energy prices aren't falling. -- Larry (11/19/19)

Flow Issues

Q: I had our plumber replace a 50 Gallon Whirlpool Water Heater that failed with a Whirlpool 80 Gallon Electric Water Heater Model # E2F80HD045V. We found that we have to turn our faucets higher to get to the hot water in the shower (single knob control) and we now are affected while in the shower if someone turns on hot water or uses the dishwasher or washing machine somewhere else in the house. This did not happen with the 50 gallon old heater.

The new water heater set at 150 degrees currently, which did not help the situation.We had the plumber replace both thermostats and elements already to be sure. In searching the net for answers, I ran across it mentioned that if the plumber soldered the output pipe to the nipple while it was attached to water heater, that it may melt the plastic (?) "heat trap" (looks like a plastic insert with pie wedges) located inside the tank attached to the hot water output line, therefore possibly restricting water flow, which would explain our issues.

1) Is this possible? 2) Can it be fixed by either replacing or removing any such "heat trap"? 3) Any other ideas? Thanks for your help in advance.

A: You could have problems with the heat traps even if the plumber did everything right. This is one of those things the federal government has foisted onto us to try to save energy and they often cause problems, either flow problems or noise problems. The solution is to replace the things with plastic-lined steel nipples and make a heat trap, if you still want one, by goosenecking a couple of flex lines. That said, your single-control shower fixture could also be at fault. Test to see if you have flow problems at any other fixture. -- Randy (1/10/10)

Q1: We have seen issues at other hot water locations throughout the house, that is why I suspect the heat trap. Thanks for the quick reply. I will see what can be done with the heat trap.

Heat Traps and Lack of Hot Water, 1

Q: My tenant said she was drawing a hot bath when she heard a "clunk" like water hammer and suddenly the hot water stopped flowing. Hot taps were dry off all over the house, but cold taps were ok. My check determined that there is no pressure in the HW tank (relief valve just drips), yet there is normal pressure in the feed line just before a straight section of copper tube without valves leading to the inlet. Ever see a tank where the inlet or dip tube suddenly closes completely?

This is a Kenmore Power Miser 10+ with a roto-swirl "self-cleaning" tube. What could have happened? I have a Sears tech scheduled for a visit, but I fear the warranty may be up. This tank is a warranty replacement from a previously prematurely-failed Kenmore, so I may switch brands if I have to buy a new one.

One piece of info: The feed was coming from a tankless coil in the furnace, so is it possible that the hot (150-degree) water entering the tank did something? I would think that any components would be able to withstand that temperature. (I have since bypassed that tankless coil, under the assumption that it may have been where the stoppage was, but it wasn't.)

A: Hello: I suspect there is a little ball in the cold inlet pipe at the heater. This makes a "heat trap" which is supposed to reduce heat loss from the tank when it isn't being used. If that ball sticks in the wrong position, flow is seriously restricted. I think I'd simply replace that heat trap nipple with a plastic lined nipple. -- Larry

Q1: You were right, the ball was stuck in the bottom of the nipple. I worked it loose with a screwdriver, then blew air into the relief valve ant the ball and cage popped out on a gusher of water. Reconnected and all is fine, we'll just suffer with a bit of hot water loss up the pipe. Hard to believe these things were designed not to fail safe. Good thing they went to flaps instead of balls.

A1: Hello: Glad it worked out. About losing heat up the pipe, you can take a long flex connector and bend it in a loop. That can act as a heat trap that will never plug up ;) You can also make a deeper heat trap by using fittings and a flex line, bending the flex into an upside down "U" to make the trap -- Larry (11/1/09)

Heat Traps and Lack of Hot Water, 2

Q: I found your Web site after reading an article in the Family Handyman and I wanted to thank you for the time and effort it took in putting it together. I will immediatly replace the drain valve on my year-old gas heater. I wondered about another problem. A friend has told me that my heater could be siphoning and that would explain why I seem to run out of hot water quickly. He said it had to to with hot water rising on the cold water side of the heater. Sure enough: my cold water pipe was hot to the touch above the shut-off valve. Any idea what is going on and how I could fix it?

A: Well, you have two issues here. Heat rises, and so does hot water, so when your tank has been unused for awhile, the hottest water is at the top, and it will also rise into the plumbing. If your tank is plumbed with flex lines, you can remove them and put in longer ones, creating a heat trap by putting a big gooseneck in the line. Then you insulate the pipe. The heat won't go beyond the trap and the insulation will keep you from losing energy.

However, I doubt that has much to do with your lack of hot water. One possibility is that you have high-flow showerheads. Changing to low-flow will help. Another is that your dip tube is broken or missing, as described in the Handyman article. A third is that your expectations are simply greater than your tank's capacity. You can run a typical 40-gallon out in 10-15 minutes, even with low-flow heads. Then you have to start thinking about a bigger tank or one with a higher recovery rate. (1995-2000)

Ins and Outs of Heat Traps

Q: I see on the Rheem web site that they sell heat trap fittings that are for the hot and cold water sides of the heater. They look like check valves. I know you have something about a heat trap "loop" and was wondering what are the advantages/disadvantages of these fittings. Thanks, Jim

A: Their primary disadvantage is that they rattle. It's especially bad if you have a recirc loop that keeps water moving. Piping does an astonishingly good job of broadcasting water heater noise. Even if the water heater is at one end of the house and you're at the other, you'll be able to clearly hear the noise, especially at night, when it can be enough to keep you awake. -- Randy

A1: Hello: There is a new type of heat trap fitting on the market that is simply a rubber flap in the pipe. When water flows, the flap is pushed aside. The advantages are that it's quiet and small. Whether it does much good (not a tight seal) or will last long are unknown. The advantages of a loop are that there are no moving parts or flow restriction. It does need to be insulated to perform well. The ball type check valve was/is an ongoing source of complaints. -- Larry (2/03/05)