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  1. #1

    Was my furnace drain plumbed right?

    I had a new high efficiency furnace installed and I'd like a second opinion on the way the drains were plumbed.

    The installer ran a 3/4" PVC pipe from the AC condenser drain to a T that drains a trickle flow humidifier to a T that hooks to the furnace condensate pump to the sump/ floor drain.

    My concern is that the humidifier creates chunks of minerals (I'm on a well system) which slew off into the drain occasionally. If those chunks block the pipe downstream of the furnace drain, it will shut down and I'll be without heat.

    Should the humidifier have it's own drain line?

    Thanks in advance for your help.

  2. #2
    Join Date
    May 2000
    Location
    Indianapolis, IN, USA
    Posts
    34,460
    Yes

  3. #3
    Join Date
    Jun 2003
    Location
    Chicago, IL
    Posts
    4,532
    As long as the PVC line has good pitch the entire way and no traps in it, you should be fine. I have never seen mineral deposits block a the drain line as long as theres pitch. However, a second drain line never hurt anyone, so as longs as there room for it, theres no problem with having two of them

  4. #4

    Confused

    Quote Originally Posted by craig1 View Post
    As long as the PVC line has good pitch the entire way and no traps in it, you should be fine. I have never seen mineral deposits block a the drain line as long as theres pitch. However, a second drain line never hurt anyone, so as longs as there room for it, theres no problem with having two of them
    There is a very slight pitch as it works it way across the plenum, then straight down to the furnace condensate inlet, then straight down 1 foot to the floor and then nearly flat 6 feet to the sump.

    In the past the humidifier has blocked a 3/4" clear flexible tube that drained it with the old furnace setup.

  5. #5
    Join Date
    Jun 2008
    Location
    Nasty Natty
    Posts
    46
    I would say if your concerned about it, have a secondary drain pipe installed to put your mind at ease. Customer service these days should be at a premium ( it is with my company) and your concern sounds legit. They should come back and make it right. After all it's a call back, but an easy fix.

  6. #6
    Join Date
    Nov 2000
    Location
    Eastern PA
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    68,962
    I agree that as long as the humidifier drain is downstream from the furnace trap assembly "AND" there is a relief vent between the furnace trap assembly and the humidifier drain, there should be no problem.

    As a matter of fact, the furnace condensate is a bit acidic and just may keep the minerals from the humidifier drain from blocking up.
    Government is a disease...
    ...masquerading as its own cure…
    Ecclesiastes 10:2 NIV


  7. #7
    Quote Originally Posted by RoBoTeq View Post
    I agree that as long as the humidifier drain is downstream from the furnace trap assembly "AND" there is a relief vent between the furnace trap assembly and the humidifier drain, there should be no problem.

    As a matter of fact, the furnace condensate is a bit acidic and just may keep the minerals from the humidifier drain from blocking up.
    Actually the humidifier is upstream from the furnace condensate trap, but I like your idea about rerouting it so the furnace condensate can keep the minerals dissolved.

  8. #8
    Join Date
    Jan 2004
    Location
    Lancaster PA
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    68,566
    Quote Originally Posted by Sharp Snips View Post
    Customer service these days should be at a premium ( it is with my company) and your concern sounds legit. They should come back and make it right. After all it's a call back, but an easy fix.
    Thats not a call back.
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  9. #9
    Join Date
    Nov 2000
    Location
    Eastern PA
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    68,962
    Quote Originally Posted by Travelover View Post
    Actually the humidifier is upstream from the furnace condensate trap, but I like your idea about rerouting it so the furnace condensate can keep the minerals dissolved.
    With the humidifier condensate being upstream from the furnace trap assembly, the pressure from the furnace blower in the humidifier drain line can adversely affect the pressure switches in the furnace. This can cause all kinds of nuisance furnace failures.
    Government is a disease...
    ...masquerading as its own cure…
    Ecclesiastes 10:2 NIV


  10. #10
    Join Date
    Jan 2004
    Location
    Lancaster PA
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    68,566
    Can you post a pic of it.
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  11. #11
    Quote Originally Posted by beenthere View Post
    Can you post a pic of it.
    Here are two views:
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  12. #12
    Join Date
    Nov 2000
    Location
    Eastern PA
    Posts
    68,962
    Yea, that's not good. Pressure from the blower in the evap coil condensate line and the humidifier overflow line can wreck havoc with the pressure switches in the furnace by fluctuating pressures through the furnace condensate line. There should be some kind of air break (vent) between the furnace line and the other two lines.
    Government is a disease...
    ...masquerading as its own cure…
    Ecclesiastes 10:2 NIV


  13. #13
    Join Date
    Feb 2009
    Location
    Fox Lake IL
    Posts
    456
    Is that a lennox furnace? If so the trap on the furnace should be on the same side of the flue pipe.If its not did thay put in the kit from lennox to drain that way.And for the trap and drain should not be set up with the tee. Make it right and it will work better.

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