Lennox Furnace Condensate Trap Leak - Need help

Discussion in 'HVAC Heating & Cooling' started by willard f, Jan 14, 2019.

  1. willard f

    willard f New Member

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    Jan 24, 2014
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    Hello,
    I have a Lennox G51MP Furnace. I recently noticed the condensate trap is leaking. I am pretty sure it is Lennox drain trap Cat # : 61M35 | Model/Part #: LB-96382A. The leak (just a slight but constant drip) is located where the pvc meets the trap's drain stub (at least that what I think it is called). See attached photos for the location of the leak.

    I have tried pushing the pvc tighter to the trap but it still drips. I have tried separating the pvc from the trap but I can't (so I assume it has been glued). I have a few questions regarding the situation and how to fix it and am hoping you can provide me some much needed help! :)

    1. Is it common practice to glue the pvc to the trap at the location of my leak?
    2. Since I cannot seem to pull the pvc out, can I just apply some glue at the source of the leak to fix this?
    3. If so, I have this Oatey PVC Cement on-hand. Is it okay to use?

    Thank you for any and all assistance!
     

    Attached Files:

  2. Reach4

    Reach4 Well-Known Member

    Joined:
    Sep 25, 2013
    Location:
    IL
    I am not a pro. I would wrap the around the white and black leaky area with self-fusing silicone tape, pulled to a low to medium tightness. I would then cover that with electrical tape. Scotch #35 white, #33+, or #66. The electrical tape will hold the silicone tape in place to let the fusing happen, and will give a little extra mechanical protection.

    I expect there is a more professional way to fix this. Silicone tape is not cheap.
     
    Last edited: Jan 14, 2019
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  4. jadnashua

    jadnashua Retired Defense Industry Engineer xxx

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    Retired Systems engineer for defense industry.
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    New England
    Have you considered taking the black part out, looking at it carefully to see what's going on? It could be cracked, or it could be a gasket is shot. It might be a simple fix. Does the parts list show a gasket where the two meet? Or, was that T solvent welded? If so, is the black part ABS? You'd need a transition cement to make that connection unless it's got a gasket to make the seal.

    This is a low pressure thing, but trying to seal most things from outside often doesn't work well.
     
  5. willard f

    willard f New Member

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    I am trying to keep my costs at a minimum and get this done with what I have on-hand if at all possible. However, this silicone tape sounds interesting. Didn't know there was such a thing. Will look into this.
     
  6. willard f

    willard f New Member

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    The black part is actually dark brown but yes it is ABS. I cannot get the two to come apart so it must have been cemented when installed. After reviewing the manual it appears there is no gasket at this connection and solvent cement is directed for use. It does call for ABS to PVC transition cement but all I have is the standard PVC. And after looking online, it appears for such minor situations like this, a standard PVC cement should be okay. Anyone see any reason why I shouldn't at least try it? Like you say, it's a low pressure drain. Worst case scenario is the glue doesn't stop the leak, at which point I I would have to just reconsider my options.
     
  7. Reach4

    Reach4 Well-Known Member

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    Transition cement is normally colored green. I don't know if it has gap filling ability.
     
  8. jadnashua

    jadnashua Retired Defense Industry Engineer xxx

    Joined:
    Sep 2, 2004
    Occupation:
    Retired Systems engineer for defense industry.
    Location:
    New England
    If the joint is cemented and it leaks, only a few possibilities:
    - the wrong cement was used
    - the pipe or fitting cracked
    - the workmanship was poor

    The cement contains some dissolved plastic and solvents. So, there is a slight amount of gap filling, but it will be really hard to evacuate all of the moisture to let it actually work reliably, long term. There's no practical way to inject the cement into the small gap, so any seal would be very thin. Suppose it doesn't hurt to try.
     
  9. willard f

    willard f New Member

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    Yes, I am guessing the wrong cement was used bc there is the faint look of glue at the connection but it doesn't appear to be green, which (as Reach4 mentioned above) is the standard color of ABS to PVC transition cement.

    It appears I did stop the drip though. For those interested, below is what I did.

    Attempt #1 - I sealed the connection with the standard PVC cement in my OP but it did not work. Guessing, as you stated, I couldn't get the gap dry enough or couldn't get the glue into the gap.

    Attempt #2 - I slathered on a bit of 100% silicone and so far this appears to have stopped the drip.

    We'll see once Summer rolls around and the AC is on blast (as I think this is when the condensate trap sees more regular activity).

    Thank you all for your time and suggestions. Much appreciated!
     
  10. Wayne

    Wayne New Member

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    Oct 9, 2020
    Location:
    Winnipeg
    The Condensate Trap in my Lennox Furnace was also leaking. I noticed that there was a hairline crack on one side. Phoning around I found out that this part is backordered with many companies. So I got a hold of my soldering gun. Made a wider grove down the hairline crack. I melted plastic from a spare piece of plastic onto my soldering gun and melted that into the crack. It works like a charm.
     
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