A/C condensate drain de-clog & cleanout: this how-to article explains procedures for cleaning or de-clogging a sluggish, blocked, or leaky air conditioning or heat pump condensate drain.

Condensate drain cleaning and unclogging tools and methods are reviewed, including simple steps that a homeowner can take to clear a blocked condensate drain at little or no cost.

Q&A on How to Un-Clog an Air Conditioning or Heat Pump Condensate Drain

These questions & answers about de-clogging blocked A/C or heat pump condensate traps or drain lines were posted originally

at CONDENSATE DRAIN CLEAN & DE-CLOG - be sure to review th advice given there.

Illustration: All-Access condensate drain line cleanout device, MSD Research, Inc., Boca Raton, discussed in the article linked-to just above.

[Click to enlarge any image]

On 2015-06-24 by (mod) - wiring wet by condensate may be unsafe

If electrical wiring is wet from any source the result can be damage and unsafe conditions.

On 2015-06-24 by gwen

Can water from clogged ac drain damage the furnace wires

On 2015-05-09 by (mod) - where is the condensate drain hole?

Donna

In the article CONDENSATE DRAIN CLEAN & DE-CLOG l see several locations at which condensate drains connect to the HVAC equipment - the exact location varies by model and installation.

On 2015-05-07 by donna

where is the drain hole on ac unit?

(May 13, 2011) Chris Nallie-Courtney said: Thank you! This was very helpful. I was able to clean out my drain line myself.

(June 22, 2011) w.m.cutler said: very educational,did all the work myself,replaced trap and cleanout 3/4 pvc,used air and shop vac. system fine now.

(Sept 25, 2011) Rana said:

Thanks so much! I was able to clean out the drain myself rather than take off work to wait for the A/C tech to come out. And I'm happy to know more about the upkeep of my own home.

(June 20, 2014) Linda Vereen said: Learned so much from your site. What a great service you provide.

Love that you post pictures and details, it makes it easy to understand.
thank You

(July 4, 2014) Rance said: Thank you so much for posting the info, etc. on ac condinsate line cleaning and the "proven" options.

Tools that you have tried and recommend. Happy and safe 4th of July to you and yours.

(May 1, 2014) Tom Kolter said:

You should check out the Jones Valve, too, available at Supco and Watso, United Refrigeration and Johnstone, the latter two as "Line Drive".

Question: AC water clogs - slope is too great on the drain

(June 23, 2011) Ma Neumann said:

A neighbor in my condo tells me that our #1 problem with the AC is water clogs--when the condensate drain's slope is too great, he says, the water rushes down the pipe and clogs up all by itself, sort of like a vacuum. I can't find any references to water clogs on the Internet.

Everything I see about clogs uses terms like sludge, dirt, debris--solid material, not vacuums. Please educate me.

Reply:

Ma Neumann:

Your neighbor's explanation makes no sense to me at all. What clogs A/C condensate lines is typically crud (dust, debris, rust flakes from inside the air handler) that collect in the condensate line trap, or at the condensate drip pan opening that feeds into the condensate line.

Excessive slope is a problem on drain lines on SEWER piping (black water, toilet waste) because if the slope is excessive the water can rush down the drain line leaving solids behind to clog the piping. But on a condensate drain line there is no sewage and no solid waste.

Question:

(July 22, 2011) Frank said:

I noticed leakage in my ceiling after a technician rewired my brand new conditioner to run at a higher fan speed which forced more air into my house. Made sense and now feels cooler. a few hours later is when I noticed the water leak.

I went into the attic and can see that there is water in the catch tray but the kicker is that there is a small hole a couple of millimeters round at the end of the tray allowing the water to leak out into the insulation down the roof into my plaster ceiling. What in the world is a hole doing in my catch tray?

Question: reader suggests de-clogging condensate drains with a digivac

(Oct 23, 2011) Anonymous said:

try a diyvac wet vac attachment to unclog the drain line .The attachment fits on the wet vac and drain line perfectly and takes a couple of minutes to unclog once vacuum is turned on.

Question: water leaking out onto furnace

(May 31, 2012) jay said:

water is coming out the top of my ac furnace

Reply:

Jay, if your unit's condensate drain pan has begun to leak, or if its drain is clogged, those would cause the leakage at the air handler as you described. There should be a removable panel to give view inside the unit to see the condition of the drain pan itself.

Watch out: water leaks onto a heating furnace heat exchanger can cause rust and dangerous heat exchanger leaks - risking carbon monoxide poisoning.

Question: AC condensate drains into a bathroom sink P-Trap

(June 26, 2012) Remo said:

Hello, it looks like my condensate drain goes directly from the ac unit down to a nearby bathroom sink and connect to the p trap. there is no way to pour bleach suck with a wet vac. when the AC kicks on, there is a horrible gorgle sound out of our bathroom sink, how can i fix that?

Reply:

Remo, it sounds as if the drain tubing needs to be disconnected and cleaned.

Follow-up

Dan, i think you are right, but how do we disconnect it? at what point, mid way? at the AC

Reply:

I'd start by trying to get inside the air handler (power off) to find the opening into the drain, and to brush clear the trap if one is present.

Question:

(July 7, 2012) M12451 said:

My ac runs but water fills up at the bottom where the condensation pump is located, I not sure what do. Can someone with good expertise please advise.

Thanks Not a HOT Summer

Reply:

M
It sounds as if either the condensate pump switch or the pump itself needs replacement

But first be sure the condensate pump is plugged in and has electrical power

Question:

(July 17, 2012) Ann Borg said:

Our condensate line backed up causing a wet drywall and ceiling....because the builder was too cheap to install an over flow valve. It has been corrected and all of the information on your website was excellent. Thank you.

Reply:

Ann, sorry to read of the condensate backup - but what "flow valve" are you referring to? It is common to drain condensate by gravity when possible, and it is also not uncommon for the condensate drain trap or line to clog with lint and crud - it's a maintenance item. Can you tell us what valve you mean? Do you mean a condensate overflow tray sensor switch?

Question:

(July 27, 2012) Jennifer said:

Hi Our 2 units have only one drain line and it seems to leak. What is the code that each line should have their own independent line?

Reply:

Jennifer, none that I know about. But the condensate drain does need to be large enough to handle the condensate flow rate without backing up; if your condensate line is leaking I suspect either it is clogged or there are improperly made leaky connections.

Question: who do I call to fix a clogged condensate drain

So if one has this issue, do I call an HVAC technician or a plumber?

Reply:

Start with your HVAC tech. who may have just the right sized tools to clear the condensate line clog. But some problems such as a clogged condensate line or a broken condensate pump are within the scope of others such as a plumber, handyman, and many homeowners.

Question: condensate water coming out of the ceiling or leaking onto the floor

(Aug 25, 2012) Rich said:

I noticed yesterday that there was water coming through the ceiling and suspected it was the A/C unit.

When I got into the attic there was no water in the drip pan or any evidence that it had been wet, and the drain lines were not clogged (did the water/bleach test and drained properly).

I opened up the unit which held the refrig evap and that inside drip pan was full and I suspect overflowed into box where the ducting is connected. The liner is soaked as well as one ducting had a puddle of water. This is where the damage to the ceiling came from.

Do I have a bad refrig evap unit or bad drip pan inside? My first thoughts were we just recently had a lot of humidity and the drip pan couldn't keep up... Thoughts? Thank you!

(Sept 9, 2012) Samantha said:

I'm noticing water dripping from the bottom of our air handler onto the floor (1st story, closet installation). I'd like to clean out the drain pipe as I'm guessing there is a clog, but there isn't any access point - should I just attach a wet vac to the outside pipe and vacuum it out? Our house came with a heil unit and I can't find anywhere to even open it up to view the drain pan itself.

Reply:

To answer this we need to look at the drip pan to see if it's clogged, rusted, perforated, leaking, overflowing, or if there is a problem with the condensate drain piping. Start at the unit.

Question: reader suggests other condensate line cleaners

Tom Kolter said:

You should check out the Jones Valve, too, available at Supco and Watso, United Refrigeration and Johnstone, the latter two as "Line Drive".

Reply:

• JV1-Jones Valve Condensate Drain Blow-Out Valve, is available from SUPCO HVAC parts, Website: http://www.supco.com/. Email: orders@supco.com, Tel: 1-800-458-2818
  The Jones JV1 blow out valve product is a plastic valve that includes a flare fitting that will allow the connection of a CO2 or Nitrogen tank of compressed gas used to "blow out" the condensate line clog. The valve attaches to a 3/4" condensate drain line and provides a 1/4" male flare fitting that incorporates a "one-way" internal Schrader valve to permit air to blow into the valve but won't leak out.

Question: risks of condensate leaks and what to do

(July 13, 2014) Altin said:

the top ac drainage is leaking, also the bottom. what is the risk and what should I do?

Reply:

Altin

The risk is water damage to the equipment - depending on where condensate is flowing; other risks include mold or other water damage, or bacterial contamination such as Legionnaire's disease.

YOu want the condensate pan fixed if it's leaking, the drain un-clogged and flowing.

Re-posting a reader's comment without disallowed link:

Stuart said:

Never Cut Or Pull Apart Drain Lines once the ALL-ACCESS AA1 is installed.
It provides easy access to clear and maintain drain lines using any method.
Please take a look at allaccessdevice dot com to learn how it works and where it is sold.

Stuart refers to a fitting that is added to the condensate drain to permit drain line cleaning by attaching compressed air, refrigerant, or possibly a vacuum.

Watch out: this fitting and its use may be inappropriate for condensate drains connected to plumbing system piping. - Ed.

Reader comment: avoid conflict of interest by readers posting product placement advertisements

26 Dec 2014
to editor

I have a concern about biased product placement in the above article.

Thanks to reader Stuart Oakner for suggesting additional discussion of the Mighty Pump as a less costly way to clear blocked air conditioning or heat pump condensate drains than calling the HVAC service technician.

But, he is the owner & salesman behind both the Mighty Pump and the All-access device. There should be an editorial policy of not allowing product inventors/sales reps or whatever to influence the placement of their own products whether they're professionals or not, at least not without an explicit disclosure.

You can see his affiliation here [references deleted for privacy] - I.H.S. [email on fiile]

Reply:

Thank you for informing us of this. It's a first to have been surprised with a sneak product placement. We will review and edit the document accordingly. Perhaps you could also identify yourself?

Reader follow-up:

I came from another web forum and noticed this guy show up and started pitching his product using third person voice. A web search led me to discover that he's doing the same thing on your site. That's how I stumbled into your page and decided to drop you a line. I think that is enough :)

-ICH

Question: water dripping from my secondary drain from the airconditioner

(Aug 16, 2014) john said:
I have water dripping from my secondary drain from the airconditioner in the front of my house.

The pan is full of water under the unit. I sucked the primary line open with a wet dry vac.

My son can hold his hand over one end of the primary drain pipe and get good suction to his hand when i am sucking with the wet dry unit on the other end.

The primary line is clear. The pan is still filling with water.

Can there be a blockage inside my unit that isn't allowing the water to flow out of the primary drain? How do I clear that?

Reply:

If the secondary or "overflow" condensate drain pan contains condensate then either there is a leak into the pan allowing condensate to leak out of the air handler or its primary condensate handling system, OR the primary condensate handling system is inoperative - typically because of a blocked pan drain opening or condensate drain line trap.

YOu'll need to shut down the system, open the air handler, examine the drain for leaks or damage or debris, clean it, and beginning there follow and clear the drain path.

Question: Does the p-trap on the condensation-line create a vacuum to remove the condensation from the unit ?

(Aug 28, 2014) Anonymous said:
On a Electrical split heat-pump system does the p-trap on the condensation-line create a vacuum to remove the condensation from the unit ?

Presently the condensation line is broken and has been detached directly at the air-handler unit, but condensation water keeps getting over into the Fan-half of the unit therefore drawing moisture into the house.

Anonymous :-) by the way the air handler is in the crawl space . . good thing huh!

Reply:

P traps do not create a vacuum nor suction to remove water from a condensate drip pan or HVAC unit. They are there to prevent backflow of gases into the unit from the drain line.

Don't spill water in the crawl space: it's asking for a mold problem.

Question: cost to have someone come out and clean the A/C water drain?

(Sept 10, 2014) Cost said:
What should it cost to have someone come out and clean the A/C water drain?

Reply:

Cost

Typically a single hour (minimum) charge service call from your HVAC company or plumber will suffice, but of course that depends on variables such as

- ease of access to the equipment
- the diagnosis of why the AC condensate (water) drain has logged
- whether other clog-related repairs are needed

At inspectapedia.com/plumbing/Water_Heater_Piping.htm

we include examples of what can go wrong with the simplest plumbing job that can result in higher costs.

Question: solutions to smelly condensate drain

(Oct 15, 2014) Anonymous said:
SO what IS the quickest, easiest way to clear a blockage?

(Nov 5, 2014) Ben Stevens said:
[ put Clorox and vinegar in the drain line on the heat pump, now I have a bad smell and burning eyes. how do I clean it up or ixit up?

(Nov 5, 2014) ben stevens635@gmail.com said:
can I replace the drain line and the smell clear up?

Reply:

Ben

If a clogged, leaky condensate drain was the cause of odors, clearing it or repairing it or replacing it ought to be the ticket. But from just your question, I can't say what's going on.

Blockages are cleared mechanically, by vacuum cleaner, by air pressure, or by line replacement (least common).

...

Continue reading at CONDENSATE DRAIN CLEAN & DE-CLOG or select a topic from the closely-related articles below, or see the complete ARTICLE INDEX.

Or see CONDENSATE DRAIN CLEAN & DE-CLOG FAQs-2 - more-recent questions & answers about unclogging a condensate trap or line.

Or see these

HVAC Condensate Articles

• CONDENSATE HANDLING, HVAC
  • CONDENSATE LEAKS
  • CONDENSATE PUMPS
  • CONDENSATE DISPOSAL, IMPROPER
  • CONDENSATE DRAINS, CODES
  • CONDENSATE DRAIN CLEAN & DE-CLOG
  • CONDENSATE DRAIN INSULATION REQUIREMENTS
  • CONDENSATE DRAIN PROBLEMS
  • CONDENSATE DRIP TRAY DEFECTS
  • CONDENSATE PAN SWITCH LOCKOUT
  • Legionella BACTERIA & HVAC EQUIPMENT
  • CONDENSING BOILER/FURNACE CONDENSATE DRAIN
  • SPLIT SYSTEM AC CONDENSATE LEAK REPAIR

Suggested citation for this web page

CONDENSATE DRAIN CLEAN & DE-CLOG FAQs at InspectApedia.com - online encyclopedia of building & environmental inspection, testing, diagnosis, repair, & problem prevention advice.

Or see this

INDEX to RELATED ARTICLES: ARTICLE INDEX to AIR CONDITIONING & HEAT PUMPS

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