+ Reply to Thread
Results 1 to 8 of 8
  1. #1
    Join Date
    Jul 2013
    Posts
    4

    Default Water in Central AC Pan

    Hello,

    We just moved into a house that has an older (probably 20 years old) central AC unit. The unit cools the house very well. We have been noticing a very sour moldy smell coming from the central AC unit. We had an HVAC company come and service the unit and Freon levels were good and he cleaned the coils inside the attic unit. However, the AC still produces that sour smell from the vents. I went up to the attic and opened the top of the unit. I saw about an inch of water just sitting in the pan under the coils. I can't seem to get to where the water drains to see if it is clogged. It drains into the gutters near the roof on the 3rd floor. Also the drain connection to the unit is sealed and I can't open the PVC piping. I called up the HVAC guy and he said if it was not draining it would be spilling over and flowing everywhere and he said it's probably not an issue. He is probably right as it has been really hot and humid here in northern NJ and is probably producing lots of water. Though I am concerned about seeing the inch of water just sitting in the pan. Is this normal? Anyone have any ideas or suggestions? Also it is the sour smell that bothers us.

    Thanx.

    --Dave

  2. #2
    Join Date
    Jul 2010
    Location
    SoCal
    Posts
    5,081

    Default Re: Water in Central AC Pan

    Some water in the pan is normal, but 1" of water is too much. However, I don't think that you have a major condensation drainage problem, just a partial blocking.

    You can probably remedy the smell situation yourself: dry the pan with a sponge and clean it with bleach. Do it when the A/C unit is off. If new water accumulates, repeat the drying and cleaning process.

    Then look in the gutter, where the water is being discharged to see if it's working, while the A/C unit is on.

  3. #3
    Join Date
    Jul 2013
    Posts
    4

    Default Re: Water in Central AC Pan

    Thanx dj1. Sounds right that it is partially clogged. Since it is an old unit when I unscrew the top cover I can just manage to fit my hand down and only get to part of the condensate pan. Unfortunately the PVC pipe drain is at the other end near the lower portion of the coils and can't see or get close to it. Though I can probably fit a wet/dry vac to suck out the water. Also unfortunately where it drains into the gutters is on the 3rd floor and can't see it drain. I would need a really really tall roofers ladder to see it and it drains to underground piping.

    1) How can I clean out the partially clogged drain pipe?
    2) I did come across some of these pan pills to drop in the condensate pan. Any thoughts on that?
    3) Do you think it's worth another call to a different HVAC company to come take another look? Maybe redo the PVC piping near the drain pan and put an opening there to unscrew to see if it is clogged? I have read that people pour bleach there to keep it from getting clogged.

    --Dave

  4. #4
    Join Date
    Jul 2013
    Posts
    4

    Default Re: Water in Central AC Pan

    Thanx dj1. Sounds right that it is partially clogged. Since it is an old unit when I unscrew the top cover I can just manage to fit my hand down and only get to part of the condensate pan. Unfortunately the PVC pipe drain is at the other end near the lower portion of the coils and can't see or get close to it. Though I can probably fit a wet/dry vac to suck out the water. Also unfortunately where it drains into the gutters is on the 3rd floor and can't see it drain. I would need a really really tall roofers ladder to see it and it drains to underground piping.

    1) How can I clean out the partially clogged drain pipe?
    2) I did come across some of these pan pills to drop in the condensate pan. Any thoughts on that?
    3) Do you think it's worth another call to a different HVAC company to come take another look? Maybe redo the PVC piping near the drain pan and put an end cap there to unscrew to see if it is clogged? I have read that people pour bleach there to keep it from getting clogged.

    --Dave

  5. #5
    Join Date
    Jul 2013
    Posts
    4

    Default Re: Water in Central AC Pan

    Thanx dj1. Sounds right that it is partially clogged. Since it is an old unit when I unscrew the top cover I can just manage to fit my hand down and only get to part of the condensate pan. Unfortunately the PVC pipe drain is at the other end near the lower portion of the coils and can't see or get close to it. Though I can probably fit a wet/dry vac to suck out the water. Also unfortunately where it drains into the gutters is on the 3rd floor and can't see it drain. I would need a really really tall roofers ladder to see it and it drains to underground piping.

    1) How can I clean out the partially clogged drain pipe?
    2) I did come across some of these pan pills to drop in the condensate pan. Any thoughts on that?
    3) Do you think it's worth another call to a different HVAC company to come take another look? Maybe redo the PVC piping near the drain pan and put an opening there to unscrew to see if it is clogged? I have read that people pour bleach there to keep it from getting clogged.

    --Dave

  6. #6
    Join Date
    Jul 2010
    Location
    SoCal
    Posts
    5,081

    Default Re: Water in Central AC Pan

    Try a wet/dry vac cleaner. If still blocked, try a small caliber snake (but it won't be able to make 90 turns). Or an electrician fish tape tool.

    Still blocked? replace the line.

  7. #7
    Join Date
    Dec 2010
    Location
    Houston Texas
    Posts
    2,360

    Default Re: Water in Central AC Pan

    Most HVAC guys use a shop vac on the outgoing end. You can also used compressed air on the inlet (messier) This is a regular maintenance chore.

  8. #8
    Join Date
    Jan 2008
    Posts
    1,096

    Default Re: Water in Central AC Pan

    Sometimes you can work a small plumbing snake into these drains, or use one of the giant ty-wraps that flexi-duct is attached with similarly. Just be very careful to not poke through flexible drain lines or push piping connections apart. More often than not, the blockage happens where the trap is located in the drain line. This is usually just outside of the pan or the unit itself. If you need to, you can cut the piping there to clean it and put it back with a coupler. When I do that with a PVC or CPVC drain,, I prefer to use a home-made 'Fernco" made of automotive heater hose and clamps so I can get to it easily the next time. Not 'code' but it works well. I also check to see if the pan is drained at the lowest point and if possible alter the pitch with bits of plastic for wedging to make it that way. If the air handler is pitched wrong I change that first, then check the pan.

    Having accumulated water in a pan is common, but it should not be accepted as "normal" because if it were, there would be no need for a drain. That standing water is going to be assimilated into the airflow making the unit work harder and possibly causing a moldy-smell issue.

    The pan is for catching the condensation water so you can get rid of it, not for holding it in place.

    Phil

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •