The Tank › Hot Water Recirculation Line Problems???
- January 4, 2005 at 4:03 pm #3097
I read a few postings trying to figure out my shower head issues in my new house. I have narrowed the issues down to the hot water side, and after reading your troubleshooting guide you mention potential issues with sediment entering the system due to the recirculation line that we attached to help out with the hot water timing. Could this be my problem and how can I resolve this forward????January 5, 2005 at 2:47 am #3099
Well, to start with, what exactly do you mean by showerhead problems? When we know that, we may be able to help.
Randy SchuylerJanuary 5, 2005 at 8:55 am #3100
We have been experieincing clogged shower heads in our master bath. When I clean them out I get white/blue particles. This is happening especially in our hand-held unit. I replaced the heads, but it reoccurred shortly after that. It tried many things to keep them unclogged (including adding a water softener) but with no luck. I have noticed that the hot water pressure to my wife’s shower (the hand held unit) is lower than the cold water pressure. The house was built with the hot water heaters (2) at the extreme far end from our master bath, a design flaw which will not happen to me again. We were having problems getting hot water to the master bath without running the hot water for a couple minutes. We resolved this by running a hot water recirculation line. It is a 1/2 inch recirculation line and all of my other pipes are 3/4 but it seems to work fine. After reading all of your postings, I noticed a theme around clogged heads resulting from recirculation lines that enter the water heater at the bottom and I light bulb went on. Unfortunately, I did not see a solution to the problem. Last night I drained a couple of buckets of H2O from the heaters via the return line valve and saw blueish setiment in the water. There is not a filter or anything between the recirulation T and the heaters. I can attach a picture if it helps. I’m just trying to get enough info to talk intelligently before I call in professional help. Thanks for any advice you can give. Your site is awesome.January 5, 2005 at 11:48 am #3101
There are a couple of possibilities. One is that your dip tube is disintegrating. This is more likely if your tank was made between August 1993 and March 1996. There was a big problem of that sort with dip tubes during that period. But dip tube failure is generally accompanied by a gradual deterioration of the ability of the tank to provide hot water.
Another is that water and sediment occasionally are being drawn backward through the recirc line. This can happen when a lot of hot water is being used. The solution is to install a spring check valve on the recirc between the pump and the tank. When anybody thinks to use a check valve at all, it’s usually a swing valve, which is more prone to stick open in hard water.
You can find a diagram of this at http://www.waterheaterrescue.com/pages/WHRpages/English/Commercial/recirc-valving.html and pictures of the valve at http://www.waterheaterrescue.com/pages/whh/pages/lingopages/spring-check-valve.html.
Hope that helps.
Randy SchuylerJanuary 5, 2005 at 12:14 pm #3102
Hello: I’ll add that a quick test to determine if it is a check valve problem is to turn off the recirc pump and close a valve on the recirc line. This will prevent any sediment from coming through the recirc line, in addition to making you wait for the hot water. If after a few days, you see no shower clogging, you can be sure a spring check walve is the right fix.
Yours, LarryJanuary 5, 2005 at 1:00 pm #3103Guest
The water heaters are less than 3 years old, so its probably not the dip tube. I think the recirc loop may be the culprit. We use the handheld unit a ton for showers, dog washing, etc. I’m sure we get to the bottom of the water heater from time to time. ALSO—the recirc line appears to be installed without a check valve at all. I will call the plumber who installed it and talk it over with him. In the least I need to install a spring check valve. Is it possible that the cause of my lower water pressure in the shower is due to the valve being clogged? Does that even make sense since it is a single handle MOEN valve that goes from cold to hot? ALSO–would a pump help out here? Thanks again for your time. This is interesting stuff.January 5, 2005 at 11:22 pm #3109
Hello: The fix for a recirc line with no pump is quite different than the fix for one which has a pump. I’d assumed you had a pump. A spring check would not work in a gravity driven recirc, (that’s one with no pump). For a gravity loop, I’d just throttle down a valve in the line to be about 3/4 closed. This will still allow the slow flow of gravity recirculation but will not allow enough flow backwards to pull sediment from the tank. Adjustment can be tricky. The advantages of a pump are quicker and hotter hot water and with a spring check valve, positively no backflow. The disadvantages are cost and possibly noise. A pump needs to be controlled with a Metlund system or timer and/or thermostat. The Metlund system would give greatest energy savings.
The shower valve could easily be clogged with sediment. I’d suggest backflushing, but if it’s pressure balanced, that cannot be done and you’ll need to take it apart to clean (after fixing the recirc loop!)
Hope that helps.
Yours, LarryJanuary 6, 2005 at 9:19 am #3111Guest
Again, thanks for your time. You are correct–no pump/gravity system.
The shower valve is pressure balanced. Can that be cleaned out? (by me?)
As far as a pump install—how much noise are we talking about? I am tempted to install one, (with a spring check valveand Thermostat/Metlund System as suggested) since it is a large house (6 baths, 2 laundrys). All of this is not in use at the same time, but the potential is there.
Finally-(I will quit milking you for free info after this) Do most plumbers know how to install this stuff properly or will they look at me like I have two heads?
Tim in STL (Go Rams).January 6, 2005 at 10:25 am #3112
Hello: In this forum, you get the benefit of having your question answered, but others can benefit by it as well. So, not milked. Try http://www.gothotwater.com to get more info on the Metlund system. If you are mechanically inclined and have the diagram for it, you can clean the shower valve, but I’d think it best to see someone who knows how, do it first.
Now about the two heads thing… how to tell you gently 😉 . Unless you can tell the plumber just exactly what you want, he will probably do what he’s comfortable with. Plumbers usually don’t like to “experiment” on clients’ homes. Pumps are not noisy. particularly if they don’t run constantly! You might ask friends, when you visit, for a tour of their mechanical rooms to listen to the pumps. I do it all the time. Let us know how it works out.
Yours, LarryJanuary 10, 2005 at 12:18 pm #3134Guest
OK–The hot water in my shower has slowed to a trickle. I ran the hot water in my seldom (never) used whirlpool tub and a ton of bluish/white stuff came out. I fear that my gravity recirc line is pulling this stuff out of my water heater and spreading it through my system. What can I do? Is there a filter or something to resolve this? What a bummer. Is there a way to clean out the Moen shower valve/cartridge?January 12, 2005 at 12:44 am #3151
Hello: To prevent junk from getting into the system through the recirc line you need to throttle down a valve on the line or add one you can close most of the way. The shower valve needs to be dismantled, flushed and reassembled. It’s all doable, but you may want experienced help. Hooking up the recic line so you can flush it would help. Proper plumbing will prevent the need for a filter. See elsewhere on this site for how to do that.
Try to think of it as an educational experience rather than a bummer.
Yours, LarryFebruary 17, 2005 at 10:03 am #3326
With a little due dilligence and a sharp plumber, my hot water nightmare has ended. Since this forum was instrumental in this process, I thought it was ony proper to post my solution.
I interviewed a few plumbers by phone and quickly found a guy who knew exactly what the deal was. He came out to my house and quicky came up with a game plan. The problem was the initial installation of my recirculation line. It was installed as a gravity only recirc line and entered my water tanks at the bottom. This allowed a ton of sediment etc to enter the recirc line and clog my showert heads and Moen cartridges. What a bummer, but a self-inflicted wound since I had the recirc line installed. I should have done more research up front.
The fix involved relocating the recirc line entry point to the top of the water heaters, installing a Taco Cartridge Circulator Pump (006-B4), a couple of valves on either side of the pump, and some backflow valves to prevent sediment from getting into the system. The plumber also tweaked the water pressure to the entire house. I had to replace a few of the Moen shower valve cartridges because they were so jammed up. It sounds complicated, but my plumber did all of this in a few hours, and now it works like a champ. Great pressure, fast hot water, and a happy wife and very clean doggy. I can send before and after photos of the install if you’d like.
Thanks for your help. Your site is great. This internet thing might just catch on.February 17, 2005 at 1:51 pm #3330
Just for what it’s worth, the plumber didn’t need to relocate the line from the bottom of the tank to the top. I’ve inspected thousands of water heaters, including hundreds of commercial tanks. Nearly all of them had the return line entering the bottom of the tank. Those that didn’t had it entering the incoming cold line to the tank. The reason: returning recirc water has cooled off and it’s considered preferable to have it go to the bottom of the tank to be reheated than to the top where it will dilute already-heated water.
Everything else the plumber did sounds right. But the check valves would prevent sediment from backflowing even on the bottom of the tank. It sounds as if your system works and you’re happy with it, so this is just for others who might read these posts.
Randy SchuylerOctober 14, 2006 at 5:34 am #5414bluegranulsParticipant
is this thread still respondable?
I have a very similar problem with hot water inlet screens at appliances clogging…
going nutz with the problem…October 14, 2006 at 1:55 pm #5419
Aluminum anode rod. Replace with magnesium.
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