Opinions on waterless trap primers.

Discussion in 'Plumbing Forum, Professional & DIY Advice' started by karsc01, Jul 6, 2006.

  1. karsc01

    karsc01 New Member

    What do the experts here think about the "waterless trap primers" such as the one sold here?:
    Are they decent? Or am I much better off with a normal trap primer if I'm doing work anyway and it wouldn't be a lot more work to use a normal one?
    Does anyone have experience with one?
    I'm putting in a floor drain that will (hopefully unless there's a problem) never see any use.
  2. Lakee911

    Lakee911 I&C Engineer (mostly WWTP)

    Columbus, OH
    I've never seen that, but it's interesting.

    How much head can it take in reverse flow before it opens admitting to flow out the drain? I know that's not the primary purpose.

    Any chance of it getting gunked up and sticking shut? I could see a case where maybe liquid laundry detergent or some other gunk flowed into the drain and it caked/dried up sealing it shut.

    Would it seal around grit, sand, pennes, screws, anything else that falls onto the floor and ends up in the drain causing it to fail open?

  3. Gary Swart

    Gary Swart In the Trades

    Yakima WA
    By chance, I'm using 3 of these in my basement. Two of them are for the remote possibility of a flood caused by a broken pipe, the other is in a small basin which serves as a mop bucket area and a drain for the water heater. I have 3/4" water supply lines than can really put a lot of water out in a hurry and this drain handles all I can put into it with no problem. I actually got these because I had had a couple of instances when the city sewer backed up into the basement. The old drains used a flapper that would stick open because of lint build up when the sewage just slowly backed up, they just wouldn't close. These newer ones just don't have the problem. Another feature that really works well is the sewer gas seal. Since the first two are not used at all, a conventional trap would dry out unless I happened to remember to prime them occassionally, which I usually didn't.
  4. karsc01

    karsc01 New Member

    That's good to know. My main concern is the sewer gas smell. I'm finishing the basement and installing an effluent pump and a bathroom, as well as moving the washer/dryer down there. So I would like to put in one or two floor drains. I'm not worried about anything backing up (except the gas) and it should be low pressure from the pump basin only (which pumps out to a septic tank). But since it's going to be a living area the smell is very important. I don't want any smell at all. If there's going to be smell I'll use a regular primer or I'd even skip the floor drain all together.
  5. Wally Pfautz

    Wally Pfautz New Member


    If you are going for a permit, better check with the inspector if he'll let you use one in lieu of a water drip primer. I'm putting in a laundry room on a second floor and will have a floor drain. My inspector won't allow the Trapguard.

  6. Huh? Eliminates P-trap?

    if I am reading this as I think I am, it saya it eliminates the trap primer while it actually eliminates the entire P trap -- the whole thing!

    This is not good, according to all my sources. Gasses do come through.

    Furthermore, if they now say they only repalce teh trap primer, is that so they can side-step around the whole issue?

  7. karsc01

    karsc01 New Member

    Well, as I read the advertisement it replaced just the trap primer. However it might as well replace the P trap too. It would be pretty useless if it's dry.
    The whole point though is that these are not supposed to let any gas through. Are you speaking from experience that they will?
  8. Two years ago, I looked into this.

    All my floor drains have P traps today.

    I didn't keep notes or put any effort into remembernig my sources on this issue, so I can't say now who told me that gasses still do come through. I know I am good at evaluating sources.

    Please note that once they claimed they replaced an entire P trap.

    This is significant. I do remember that claim.

    Now, I recognize the same image and I see no discussion about replacing the P trap entirely. If I had to draw an immediate conclusion, I would say that somehow they were forced into reducing their claim to a lower level so as not to fall afoul of the Code police or some equivalent... You get the picture. Does not reassure me at all.

  9. I shot this product down in one of the forums I moderate.

    #1 reason

    Rubber over time does crack and will hold memory to certain positions it is made in. It will also hold waste matter incoming if it isn't cleaned after its use.

    AZDC PLUMBING New Member

    One hand or other but in the end great product

    Waterless trap primer are great! Have had no problems with them and if you have an existing drain with no trap primer this is a great way to block gases when you can't get into the wall and floor to put in a water primer. Here you have as well as else where. Problem with the water primers going bad and people don't even no it in till it leaks all over the floor or in the wall, runs your water bill up run water down the drain and they are 3 times the cost as the waterless trap primers and would never take out the p-trap the are to be used in line with the waterless primers. So the rubber wearing out is still cheaper replacing the waterless ones that going into the expense of a water primer and all the parts that go with it per code when istalling new or replacing a bad one. We have about 30 of them out with no problem and been in for at least 3 years. You can fight the inspector on the uses of them go to the web site of trap gaurd and download the paper on waterless trap primers and are legal by code as a alternative to water primers.
  11. shacko

    shacko Master Plumber-Gas Fitter

    Rosedale, Md
    AZDC Plumbing:
    >>>You can fight the inspector on the uses of them go to the web site of trap guard and download the paper on waterless trap primers and are legal by code as a alternative to water primers.<<<

    It doesn't matter what someone else says, if the code says you can't use it, you can't!
    Last edited by a moderator: Sep 4, 2010
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