How JustAnswer Works:

  • Ask an Expert
    Experts are full of valuable knowledge and are ready to help with any question. Credentials confirmed by a Fortune 500 verification firm.
  • Get a Professional Answer
    Via email, text message, or notification as you wait on our site.
    Ask follow up questions if you need to.
  • 100% Satisfaction Guarantee
    Rate the answer you receive.

Ask Douglas Your Own Question

Douglas, HVAC Technician
Category: HVAC
Satisfied Customers: 3065
Experience:  Manufacture Rep for Major Brand, Technical Trainer, NATE
Type Your HVAC Question Here...
Douglas is online now
A new question is answered every 9 seconds

Why is my heat pump/air conditioner leaking water onto my basement

Customer Question

Why is my heat pump/air conditioner leaking water onto my basement floor? I assume it is condensate since the puddle is not that large. My unit is many years old, installed when the house was built in 1993. I changed filters but am not sure I have the right size. I took out 25 x21 x1's but can only find 25 x 20's in local hardware//bigbox stores. Help.
Submitted: 4 years ago.
Category: HVAC
Expert:  Douglas replied 4 years ago.
Hi, I'm Douglas and I am here to help you resolve problems with your heating and cooling equipment.

Most likely, it is indeed condensate as you suspect.

It may be one of several things.

  • Over time a coil may get dirt on it and water does not "sheet" as well as it once did. It can form a drop if it his a hunk of dirt or a dry spot on the coil. Especially if your filter doesnt fit correctly.
  • If it's that old, it may have a metal drain pan which may be rusted through and can leak. Even a plastic pan can have a crack in it.
  • If your unit has frozen up, when it thaws, it can drop hunks of ice into the lower end and that melts.
  • The drain could be slow and just need blown out.
  • The refrigerant line (the large insulated one) may just need the insulation repaired, it could be sweating and dripping
  • The condensate drain can also sweat if the water inside is cold enough.
Is there an auxilliary drain pipe?

You may have to open the air handler door and inspect the drain. There should not be much water in the pan (a little). If it is deep your drain is either restricted or not properly trapped. If it's metal, look for rust, if it's rusty, it may just need a new drain pan. You really cant see the part of the coil that would get dirty, it would be on the incoming aire inlet side of the coil.
Douglas, HVAC Technician
Category: HVAC
Satisfied Customers: 3065
Experience: Manufacture Rep for Major Brand, Technical Trainer, NATE
Douglas and other HVAC Specialists are ready to help you
Customer: replied 4 years ago.
It sounds like it could be the drain. The water seems to collect around the base of the unit and does not apear to be dripping from the refrigerant line. Have no idea if there's an auxilliary drain - I view this thing as a magical metal box that heats & cools the house without much interference from mortals! But it has been quite a while since any service was done on the unit so it may be time to call in a local technician. At least I now have some idea of what problems I am having and can ask intelligently for repairs. I thank you for that.
Expert:  Douglas replied 4 years ago.
If you can see the end of the drain (maybe it goes to a floor drain) you can try to attach a shop vac to it and see if it pulls a bunch of goop along with the water. Sometimes that does tha trick.
Customer: replied 4 years ago.
no floor drain visible - house is built on a floating slab. No shop vac. You're dealing with a technically inept grandmother. But another thought to have in mind for a repair person.
Expert:  Douglas replied 4 years ago.
a tech uses a device called a gallow gun. Think of one of those CO2 cartriges used for whipping cream or in some pellet guns. They use this to blow the drain out.

I would probably suggest getting it serviced while it's only a small problem. Use a reputable HVAC service company and if you dont know any ask your friends and family. The yellow pages are full of "hacks" and "cheats".

If I have been helpful, please click accept and I wish you the best. Nevermind, I saw you already did

JustAnswer in the News:

Ask-a-doc Web sites: If you've got a quick question, you can try to get an answer from sites that say they have various specialists on hand to give quick answers... seen a spike since October in legal questions from readers about layoffs, unemployment and severance.
Web sites like
...leave nothing to chance.
Traffic on JustAnswer rose 14 percent...and had nearly 400,000 page views in 30 days...inquiries related to stress, high blood pressure, drinking and heart pain jumped 33 percent.
Tory Johnson, GMA Workplace Contributor, discusses work-from-home jobs, such as JustAnswer in which verified Experts answer people’s questions.
I will tell you that...the things you have to go through to be an Expert are quite rigorous.

What Customers are Saying:

  • You did one super job of explaining to me everything there is to know about this fridge. I'm looking forward to asking you questions in the future. Jimmy Bagley, IA
< Previous | Next >
  • You did one super job of explaining to me everything there is to know about this fridge. I'm looking forward to asking you questions in the future. Jimmy Bagley, IA
  • Wonderful service, prompt, efficient, and accurate. Couldn't have asked for more. I cannot thank you enough for your help. Mary C. Freshfield, Liverpool, UK
  • This expert is wonderful. They truly know what they are talking about, and they actually care about you. They really helped put my nerves at ease. Thank you so much!!!! Alex Los Angeles, CA
  • Thank you for all your help. It is nice to know that this service is here for people like myself, who need answers fast and are not sure who to consult. GP Hesperia, CA
  • I couldn't be more satisfied! This is the site I will always come to when I need a second opinion. Justin Kernersville, NC
  • Just let me say that this encounter has been entirely professional and most helpful. I liked that I could ask additional questions and get answered in a very short turn around. Esther Woodstock, NY
  • Thank you so much for taking your time and knowledge to support my concerns. Not only did you answer my questions, you even took it a step further with replying with more pertinent information I needed to know. Robin Elkton, Maryland

Meet The Experts:

  • Phil

    Mechanical Engineer

    Satisfied Customers:

    Retired HVAC/ Electrical & Boiler contractor. Industrial
< Last | Next >
  • Phil's Avatar


    Mechanical Engineer

    Satisfied Customers:

    Retired HVAC/ Electrical & Boiler contractor. Industrial
  • gotoman for ac's Avatar

    gotoman for ac

    HVAC Technician

    Satisfied Customers:

    51 years of experience install design and repair of all makes and models of AC
  • Rick Mather's Avatar

    Rick Mather

    HVAC Technician

    Satisfied Customers:

    35 years experience, HVAC
  • Matthew's Avatar


    HVAC Technician

    Satisfied Customers:

    14 years experience in the HVAC field of service, installation, Manual J & D calculations
  • Kenton Guidry's Avatar

    Kenton Guidry

    HVAC Technician

    Satisfied Customers:

    12 years install/service experience.
  • Rick Ridley's Avatar

    Rick Ridley

    UK Heating Engineer

    Satisfied Customers:

    Retired But have had 30 years on the tools, Ex CORGI
  • Tom's Avatar


    HVAC Technician

    Satisfied Customers:

    16+yrs HVAC/R service. Residential Commerical Industrial