I have a water pump similar with this one
enter image description here

In this question I am asking bout what is marked with #3 in the picture. In my case that pipe goes to the ceiling ..partially open in the furnace room and from there through the finished ceiling it traverses a hallway and I am not sure if it joins the drain of my bathroom downstairs or the drain of my sink or bathube upstairs, they are all represented in the picture. enter image description here I need to verify the integrity of this pipe. How can I do it?

Edit: the drain tube was installed about 30 years ago when the old furnace was installed (an Olsen, first models of condensing furnaces)

Edit2: looking closer I discovered that there is a pipe that brings water to my humidifier (old an and not in use anymore. Most probably the tube for the pump follows this pipe to the source of water. The worst part is that I also discovered that just above the furnace the tube diameter it reduced by coupling the initial tube with a smaller diameter tube which is the one that actually goes through the floor joists, have no idea where. So now it is out of question to use fishtape to see where this tube goes.

  • Pipe? or plastic tubing? It sounds like corners have been cut here.... – Tyson May 24 '16 at 0:18
  • it is plastic tubing all the way as far as I can see which is just in the furnace room. From there it enters the ceiling and I can not see it – MiniMe May 24 '16 at 0:20
  • it shouldn't be plastic tubing for that usage. If there is no floor drain in the furnace room, then an official "drain" should have been installed above the furnace, and your lift pump should be draining to that. The entire furnace should be sitting in a drain pan with a second pump. Failure of the primary system should result in leakage to the drain pan, that should use a different drain pump. – Tyson May 24 '16 at 0:29
  • I had it installed by authorized HVAC guys and they did not say anything about these. It is true that the installed only the new furnace and the AC, the pump was already there from the old furnace – MiniMe May 24 '16 at 0:44
  • 1
    I don't think you need a drain pan if the furnace is in a basement. You could use a wet switch shut off in case the condensate pump quits working. The only way I can think to pressure test it, is find the other end as Tester suggested. Plug the end of it with a pipe plug and hose clamp, and then put compressed air on the other end. – ArchonOSX May 24 '16 at 1:23

I was reading this webpage http://inspectapedia.com/aircond/Condensate_Drain_Problems.php and I came across a comment that inspired me a method to check if my tube is OK. That would be to use a smoke bomb (search this keyword on that page) in a shop vac and to pump the smoke through the tube to see where it connects. This will work assuming that at the other end the tube is connected to a drain in one of the ways described here: http://inspectapedia.com/aircond/1633s.jpg If that is the case then the smoke will come out at the other end in the kitchen or bathroom and with that we located the other end of the tube. Having that location then we can easily conduct a pression test as suggested in one of the comments above

  • Don't use a smoke bomb. They make aerosol cans of smoke for testing smoke detectors. Pricier than smoke bomb, but much easier to control and less dangerous. – longneck Jun 1 '16 at 12:58
  • This is certainly better than trying to break a 30yo plastic hose by putting 120psi air through it. If it ain't broke, don't fix it. The only way to be sure is to ---nuke it from orbit--- I mean, um, run a new line. – Mazura Oct 1 '16 at 0:16
  • It is broken and I can not run a new line without extensive demolishion, the basement is finished and I do not have access to my plumbing and to the ceiling in basement – MiniMe Oct 1 '16 at 14:35

That tube appears to be an effluent (outgoing) tube for the condensate pump; this is a pretty typical installation where the condensate leaves the furnace or air handling unit (at arrow #2, which is not quite piped correctly, should have a trap and vent if that is in a draw-through configuration); and then it goes to the condensate pump (at arrow #1), and that pump sends the condensate out to an approved drain location (under a sink at a hub drain with a little air gap is common).

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