GAS Furnace HVAC downdraft leaking water???

Discussion in 'General Plumbing Help' started by guest, Jan 24, 2020.

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  1. Jan 24, 2020 #1

    guest

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    I have a high efficiency downdraft gas furnace. When the unit runs a for a longer time due to the cold weather, water comes out of the bottom of the unit (A coil area). The entire area and next room carpet ar getting wet, The blowers on the unit are working and no error code coming for th unit.
    I need some help with this. So strange!!!
    Thank you for you advice!
     
  2. Jan 24, 2020 #2

    voletl

    voletl

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    How did the unit get rid of the condensation it creates is it piped into a drain or is there condensation pump
     
  3. Jan 24, 2020 #3

    Mitchell-DIY-Guy

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    This has happened to me in the past. Turned out to be a clogged drain line...specifically in a somewhat unnecessary miniature "P" trap that had collected too much gunk in the bottom. As this drained to a sump--no physical connection-- it really wasn't necessary. The HVAC guy removed the trap, and all was well. Astounding how much condensation this made...a total mess of the floor in the crawl space.
     
  4. Jan 24, 2020 #4

    Jeff Handy

    Jeff Handy

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    This happens a lot.
    When natural gas burns, it creates water.
    Modern furnaces don’t send that vapor up the chimney, so instead it collects in a pan and runs to a drain line.

    If you remove the access covers, you will find the drain line.
    It is usually behind the lowest cover door.
    Or trace it back from the drains you see outside your furnace.

    You will probably see a black hose attached to some fittings with cheap hose clamps.
    I remove one of these, and replace with a stainless screw drive hose clamp

    Take it apart somewhere, near where it leaves the furnace, enough where you can get your mouth onto it to blow very forcefully back into it, several times.
    You will hear water gurgling.
    Backed up water might come trickling out.

    If you are squeamish, you can adapt a piece of garden hose to it, and blow hard into that.
    Or use compressed air, leaf blower, whatever, if you are a big wussy!

    Sometimes, the flexible condensate hose is extending outside the furnace, and you don’t need to take anything apart, just blow right into that.

    I have clients where I do this once a month, from October til April.
    For all three of their furnaces.

    Their hvac guys were charging a fortune in service calls for this, and they were still getting occasional nuisance flooding.

    My crude method has worked perfectly for at least seven years.

    I also rinse out the external pvc drain lines with hot bleach water, followed by a fairly gentle rinse with water through a hose attached to the water heater drain.

    Once a month, year round.

    The humidifiers and a/c coils also generate crud and slimy gook that plugs up these long drain lines that run to a sump basin.
     
    Last edited: Jan 24, 2020
  5. Jan 27, 2020 #5

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    Thank you for the reply. The condensate is piped directly into the drain. It actually has 2 drain tube that drain into a drain attached to the middle side of the furnace, the water drips into it then it drain into the floor drain.
     
  6. Jan 27, 2020 #6

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    Thank you for your reply and suggestions, I have already performed those items, I have not found the hoses to be plugged or to gurgle with water. This is really crazy as I Know the water / condensate has to be coming from from the heat vent. Help!
     
  7. Jan 27, 2020 #7

    wood4d

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    It sounds like a 90% furnace with two drains running to a trap on the side of the unit. Those are from the heat exchanger and draft inducer. Its unlikely that the heat exchanger is damaged internally since it is inside the furnace and well protected. It seems if that was damaged water would be running out the ductwork. the draft inducer is plastic and hard to damage also. The most likely culprit is the tubing connections. Post a photo.
     
  8. Jan 28, 2020 #8

    breplum

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    Good photos might help. Along with brand and model maybe...
    Many 90+ AFUE furnaces develop micro cracks in the collection boxes.
    Often covered under the mfr's warranty, but not always.
    This is not really a home handy-person fix unless you are very careful.
     

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