HVAC Tech Help Trane XV90

Discussion in 'The Okie Corral' started by Big Bird, Jan 2, 2010.

  1. Big Bird

    Big Bird NRA Life Member

    Messages:
    11,920
    Likes Received:
    4,561
    Joined:
    Aug 7, 2003
    Location:
    Louisville KY
    Need a little input from some HVAC techs.

    I have a Trane XV90 3 ton furnace with Heat pump. Currently its too cold for the heat pump so the natural gas is kicking on as it should.

    Recently I have noticed water on my basement floor but it was hard to trace the origin because it wasn't much and most of the time by the time I noticed it it was dry in many spots so the exact origin was hard to spot. But today I clearly saw a trail coming form the furnace. I opened the service panel and found a rust spot about the size of a silver dollar on the bottom of the unit right under the hoses used to connect the unit to the small pump on the outside used to move the water across the basement to my sump. The little elbow shaped hose attached to the white plastic box on the right side off the panel had come loose and water was dripping out. No biggie. I reattached the hose and that should stop the leak.

    My question is why is there water when the furnace is on? I understand water when the AC is working... But where is this water coming from? Is this simply condensed water vapor from the Natural Gas?

    Thanks
     
  2. DWARREN123

    DWARREN123 Grumpy Old Guy

    Messages:
    10,646
    Likes Received:
    6,127
    Joined:
    Jan 25, 2008
    Location:
    Clarksville, Tn.
    Deferential of temperatures cause condensate. Heated exhaust will condensate moisture from cold air.
     

  3. MooseJaw

    MooseJaw NRA Lifer CLM

    Messages:
    9,178
    Likes Received:
    1,127
    Joined:
    Feb 12, 2002
    Location:
    AridZona
    I believe you have a "Condensing" furnace.. high efficiency, with PVC pipes going in and out of the furnace.

    It's normal for some condensation to occur..

    Your installing contractor should have piped a drain line away from the furnace.. this happens on newer water heaters also..

    Check the installation instructions, and call him back if it's not right.
     
  4. sawgrass

    sawgrass

    Messages:
    3,328
    Likes Received:
    34
    Joined:
    Feb 21, 2009
    Water vapor is a bi-product of combustion. Because you have a high efficiency furnace, it actually condenses the water out in the secondary heat exchanger. It's very common to have a condensate pump outside of
    the furnace for the condensate. It's also recommended that you pour a
    gallon of water with a little bleach in through these pumps every six months if they are used year round. (Heating and Cooling)

    After putting the hose back on, check to make sure the water drys up.
    If you continue to see water, call your contractor, as it could indicate
    a problem with the secondary heat exchanger.
     
  5. G30Jack

    G30Jack .88 Magnum

    Messages:
    2,272
    Likes Received:
    16
    Joined:
    Apr 17, 2002
    Location:
    Shoots through schools
    Check your drain. I had to blow mine out last year because I let crap build up. I now pour a cup of bleach into the drain (monthly, when I change the filter) for the humidifier and the condensate drain for the AC to keep the algae growth down.
     
  6. Big Bird

    Big Bird NRA Life Member

    Messages:
    11,920
    Likes Received:
    4,561
    Joined:
    Aug 7, 2003
    Location:
    Louisville KY
    Thanks for all the replies. Yes...the furnace has PVC vent lines that go outside. I already knew about the bleach in the drain pump and have been doing that. I put on a new metal hose clamp as the little plastic squeeze clamp used byt the contractor was no longer doing its job. The water on the floor is gone. So I seem to have solved the problem. I knew that water/condensation was a product of natural gas combustion. I just thought it was vented out with the hot exhaust like used to happen with a more conventional furnace. I work a good deal in my basement and just never noticed the drain pump kicking on in the winter like it does when the AC runs. But its pretty quiet so I may have not been listening for it.

    I love my furnace/heat pump combo. The heat pump does a great job until temps get below freezing and then the natural gas furnace kicks in. Its cut my heating bills nearly $50 a month over the old 50% efficient gas burner I had before. The variable speed fan and the heat pump are what make the difference in my bill though!