Recirculation pump removed.

Discussion in 'Plumbing Forum, Professional & DIY Advice' started by INTP, Jan 13, 2006.

  1. INTP

    INTP New Member

    My 40 gal gas hot water heater developed a small leak, so I'll be replacing it today. I looked at the lines and realized that the previous installer did something unusual in hooking it back up, since there used to be a recirculation pump which has since been removed. I'm not sure I want to hook it back up the same way...

    What they did was to cut off the drain valve on the bottom of the water heater and solder in a T fitting, and put the drain back on. This line now feeds into what looks like a check valve, then reduces from 3/4" to 1/2" copper, then into the slab. (The house is slab on grade, built in 1969). The other lines(in/out/presure relief) look ok.

    Not only is this drain connection odd to me, but I also suspect it may be a part of the reason why the master bath takes so long to get hot water (about 2-3 times the other bathroom, roughly the same distance). I'm guessing that the relatively cooler water from the bottom of the tank is feeding into this line, and combined with there being two lines, they add up to slower warm-up. If I could improve this situation, I'd be happy (and more importantly, so would my wife ;) ).

    Can anyone suggest the best way to reconnect this?

    If it helps, I don't mind cutting drywall on the other end if needed, but would rather not get into (or under) the slab. I'm thinking that the best solution would be to cap the other end of the extra line and just leave the one line feeding the master bath. If I cannot get to the other end, I'm thinking that both lines should feed off the output of the water heater and not come from the bottom.

  2. return line in the slab??

    it sounds like you got the return line
    instaloled in the slab.....that is not a good set up at

    its best to eliminate that line in the floor and see what
    happens, most copper retune lines will eventually start getting
    pin holes in them, and in the slab you cant find them..

    you could already have one in the floor and not know it....

    if thier is a pin hole , it might make the water heater work
    extra more and wear it out quicker..

    at the very least put a ball valve in the line going into tthe floor
    to isolate that run and see if you still get hot water to the furtherst
    area of your home...

    if you can figure out where it ties in on the other end it
    might be prudent to cut that line out all togetheor
  3. INTP

    INTP New Member

    Thanks for the suggestion. I'll definitely put in a ball valve. There could be a small leak, but I have recently checked the water meter and there's no sign of flow with all the valves closed. (knock on wood).

    I'm pretty sure the copper lines are all under the slab and the lines just comes through the slab where the fixtures are (based on my neighbor's experience fixing a leak) and at the water heater.

    If you had to guess, where would you look for the connection at the other end? I'm almost certain that it was for the master bath. The master bath has a sink, a tub, and a shower. I don't mind cutting the drywall under the sink to peek, and I can get to the wall at the shower and tub with only drywall and wallpaper to repair. But what are the chances that it's under (or in) the slab?

    And if I cannot cap both ends, then will it introduce stagnant water from the now non-flowing line if I only cap one end?

    Thanks again.
  4. Gary Swart

    Gary Swart In the Trades

    Yakima WA
    I installed a recirculation system in my home and it works beautifully. For the return line, I removed the hose bib in the tank and replaced it with a nipple and tee. From this I have a valve on one side to drain the tank and the return line on the other side. I have no pipes in the floor and all hot water pipes are insulated. In order for all fixtures to obtain the virtually instant hot water, the return line must be as close as possible to each fixture. On a retro fit, it may not be possible to get the return line really close, and in that case you will not have hot water as quickly as fixtures where the return line is close. I've found that 5 or 6 feet isn't noticably different from 2 or 3 feet, and even up to 10 or 12 feet, while noticable, doesn't have a long delay.
  5. jadnashua

    jadnashua Retired Defense Industry Engineer xxx

    New England
    If I had to guess, I'd guess there is a t fitting probably behind the vanity, but maybe the shower, to allow the hot water to be circulated back to the water heater. If the check valve back at the water heater is defective, when you open a valve in that bathroom, it could be drawing water from both the top and th ebottom of the water heater...since the hot water rises, the mix would end up being cooler. My unprofessional opinion.
  6. try the shower

    somewhere around the shower

    if you cant see the pipie due to a finished basement, ect...

    its anybodies guess....

    shutting off that line, wont cause you any stagnant water problems....
  7. INTP

    INTP New Member

    Again, thanks for the replies. I'm going to try to find the fitting where it returns at the master bath, and if so I'll cap it off at both ends. Otherwise, I'll leave it capped on the water heater end, and NOT modify the water heater drain as the previous installer did.
  8. INTP

    INTP New Member

    I always feared that the water heater would burst and there would be water everywhere. Well, in this case, the leak was slow, and had apparently been there a while before we noticed it because there is a lot of mildew (no drain pan was installed the last time, but I will be installing one this time) It looks like I'll be getting more drywall practice after everything dries out. :(

    I've soldered a ball valve on the return line, and then put a cap on the line that can be cut off if anyone every wants to hook the pump back up later. I'll probably even be nice and label it.
  9. hj

    hj Moderator & Master Plumber Staff Member

    Cave Creek, Arizona

    1. If the circulation/return line is under the floor it is impossiblefor it to work without a pump.
    2. the check valve is probably defective and allowing the cooler water at the bottom of the tank to backflow to the point of connection, which is probably at your bathroom tub.
  10. INTP

    INTP New Member

    I'm finished with the water heater swap, and I wanted to follow up and thank everyone again for their feedback.

    As I mentioned above, I left the return line capped at the water heater. The result is that the time it takes to get hot water in the master bath has gone from about 2 minutes to about 20 seconds. Although I didn't test it, I am quite certain that the check valve was bad. It was located below the water heater, which was full of sediment, so I'm sure that didn't help at all.

    I do want to emphasize that you've helped me gain major brownie points with my wife. :D

    (and just to clarify, I didn't want the pump in the first place. I know it's wasting a bit of water, but it's using less energy.)
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