To avoid these ads, REGISTER NOW!

AC drain pan?

Chaznsc

Well-known member
Joined
Apr 9, 2013
Messages
6,526
Location
SC
Long story short.....

Had my upstairs AC unit replaced last summer. The asshats who I hired managed to flood my upstairs......TWICE. Anyhow, the unit went off tonight, and I knew it was being completely **** off simce nothing was running. So I crawl into the attic and the pan is full of water and the switch activated fortunately. The problem (I think) is that the pan has no drain line.....shouldn't it? The unit above has a condensate line which does drain outside and I think it got backed up, as I blew into it and felt something give way.

But shouldn't the pan be connected?
 
To avoid these ads, REGISTER NOW!

torqueman2002

Well-known member
Joined
Jun 3, 2009
Messages
6,138
Location
SE Michigan
Ours is, now. It was a hassle to get the original installer to correct it. That was just 1 of the things on the list the crew of clowns messed up.
 

crf731

Well-known member
Joined
Oct 8, 2011
Messages
414
Yep. Mine does.

The one that is built into the AC unit drains into the plumbing drain for the house. The backup pan underneath the AC unit drains out under the eaves on the house.
 

er3456df

Well-known member
Joined
Dec 1, 2009
Messages
230
No.

The switch is there to let you know your drain is clogged. If that second pan had a drain line, you wouldn't know until both were clogged. Not really any point to that, now is there? Meanwhile, your pan inside the unit is constantly full, overflowing, and rusting away the inside of your equipment- which goes unnoticed until that switch trips.

HVAC installers may be clowns- HVAC engineers, not so frequently.
 

K'ledgeBldr

Well-known member
Joined
Aug 22, 2011
Messages
1,925
Location
Johns Creek, GA
From IRC:


M1411.3 Condensate disposal.
Condensate from all cooling coils or evaporators shall be conveyed from the drain pan outlet to an approved place of disposal. Such piping shall maintain a minimum horizontal slope in the direction of discharge of not less than 1/8 unit vertical in 12 units horizontal (1-percent slope). Condensate shall not discharge into a street, alley or other areas where it would cause a nuisance.


M1411.4 Auxiliary drain pan.
Category IV condensing appliances shall have an auxiliary drain pan where damage to any building component will occur as a result of stoppage in the condensate drainage system. These pans shall be installed in accordance with the applicable provisions of Section M1411.3.

Exception: Fuel-fired appliances that automatically shut down operation in the event of a stoppage in the condensate drainage system.


The AHJ's that I always dealt with required one or the other- either a drain line (preferred) or a float switch. One or the other is your redundancy, both would be...

Well, redundant- déjà vu all over again.
 

larry4406

Well-known member
Joined
Jan 27, 2006
Messages
18,986
Location
Northern Virginia
I build new production homes in MD and VA Our units are provided with a main condensate drain, an overflow pan, an overflow pan drain, and a float switch in the pan.

For the units in the attic, the overflow pan drain exits out the soffit and is centered on a window. Customers are informed that the drain is an emergency overflow and normally there would never be condensate coming out the pipe. It is placed over a window so that drainage would be obvious. The main condensate drain is routed internal to the home to the basement to a floor drain or sump crock.

For units that are in the basement, we again provide this same defense in depth, but the drains are routed to the floor drain or sump crock. In the counties I build, un-metered water (i.e. condensate) cannot be run down the sewer system. The floor drain is connected to the sump crock.
 
OP
C

Chaznsc

Well-known member
Joined
Apr 9, 2013
Messages
6,526
Location
SC
No.

The switch is there to let you know your drain is clogged. If that second pan had a drain line, you wouldn't know until both were clogged. Not really any point to that, now is there? Meanwhile, your pan inside the unit is constantly full, overflowing, and rusting away the inside of your equipment- which goes unnoticed until that switch trips.

HVAC installers may be clowns- HVAC engineers, not so frequently.

It would seem a drain makes sense since the unit is in the attic. I mean, dragging a shop vac into that space isn't any fun. The crazy part is on the first two installs they had the pan connected. Third attempt they disconnected and capped the drain.
 

JakeKohl

Well-known member
Joined
Feb 23, 2012
Messages
1,365
Location
Greenville, SC
My pan has a drain that tees into the drain for my unit. The drain pipe extended down the side of the house and practically stopped just at dirt level - it clogged once (and I shortened it up). With the drains configured this way, when the drain line clogs up, it fills the pan and hits the float switch and shuts down the unit. When you clear the obstruction in the pipe, the pan also drains itself and all is well again. tadaaaaaa.
 
Last edited:

Trey T

Well-known member
Joined
Aug 3, 2011
Messages
3,749
Location
Houston, TX
Any attic air handler will have two condensate drip pan:
1. primary pan is inside the handler - this one should never overflow into the secondary pan. If there is an "active" sewer line nearby, tap into it w/ a p-trap.
2. secondary pan is under the handler - this should flow outside. This pan should not receive any water if primary pan does its job.

If you have clog, it might be that you do not change the filter often enough.
 
To avoid these ads, REGISTER NOW!

catchlizzy

Member
Joined
Jul 6, 2013
Messages
10
If it's like my house, your A/C unit in the attic should have a primary drain to your house plumbing. In most cases, it drains into your upstairs bathroom drain. You can usually see a Tee from your bathroom sink p-trap to a PVC pipe running into a wall (up to your A/C unit in the attic). When the Tee is clogged, condensation from the A/C will overflow to the drain pan. I've learned the hard way when this happened. But my pan had a hole that drains the water to the outside of my house. However, the water in the galvanized pan eventually rusted the pan so I had rusted water flowing outside and stained some of my brick. So now every spring, I disassemble the bathroom Tee's and clean out any buildup. After that, I pour a cup of bleach down the PVC from the attic A/C to the bathroom drain. Now, I have no water in the drain pan every A/C season.
 

er3456df

Well-known member
Joined
Dec 1, 2009
Messages
230
It would seem a drain makes sense since the unit is in the attic. I mean, dragging a shop vac into that space isn't any fun. The crazy part is on the first two installs they had the pan connected. Third attempt they disconnected and capped the drain.

Drains clog. True story. Why not put a 3rd pan under that one, so that if the second drain backs up it'll go into *another* pan, this way you'll never have to maintain your equipment at all?

(Until the 3rd drain clogs- OMG, what now????)
 

rlitman

Well-known member
Joined
Oct 18, 2010
Messages
24,579
Location
Long Island
Yes, the catch pan should be drained, so that if the regular condensate drain overflows you don't have damage.
But the catch pan should ALWAYS be dry. If water hits it, your regular drain failed.
So, you can get a flood alarm sensor and put it in the catch pan. If it is screaming, you now have some time to fix things.
 

TEXACMAN

Well-known member
Joined
Feb 6, 2006
Messages
284
Location
Mount Pleasant Texas
Your emergency pan should have a drain line that goes outside and drip in front of window so you know you have a problem. It may have a drain behind the unit in emergency pan and it could be stopped up with insulation etc... You need it to drain , the emergency float will still shut unit off to warn you and shut back on when it drains. The air handler should have a drain hooked up to main plumbing in house but some companies will run it outside even though it is not correct.
 

brihvac

Well-known member
Joined
Dec 21, 2011
Messages
484
Location
North Wilmington, Delaware
I build new production homes in MD and VA Our units are provided with a main condensate drain, an overflow pan, an overflow pan drain, and a float switch in the pan.

For the units in the attic, the overflow pan drain exits out the soffit and is centered on a window. Customers are informed that the drain is an emergency overflow and normally there would never be condensate coming out the pipe. It is placed over a window so that drainage would be obvious. The main condensate drain is routed internal to the home to the basement to a floor drain or sump crock.

For units that are in the basement, we again provide this same defense in depth, but the drains are routed to the floor drain or sump crock. In the counties I build, un-metered water (i.e. condensate) cannot be run down the sewer system. The floor drain is connected to the sump crock.

+1
I always do that or put it right over a door way
 

TEXACMAN

Well-known member
Joined
Feb 6, 2006
Messages
284
Location
Mount Pleasant Texas
There are bad techs out there whether it is HVAC , PLUMBING , ELECTRICAL ETC... Just like there are crooked LAWYERS , incompetent DOCTORS and so on. You can trust most companies to make it right because there service business depends on it, they want you happy so you will keep using there services. Doctors are going to tell you to **** it if they screw up because you have to prove it and have the cash to sue.:(
Anyway hope you ( O.P.) get it repaired right by contractor and it all works out for you.
 

torqueman2002

Well-known member
Joined
Jun 3, 2009
Messages
6,138
Location
SE Michigan
Ours is, now. It was a hassle to get the original installer to correct it. That was just 1 of the things on the list the crew of clowns messed up.
We brought in a 2nd company to estimate corrective action. After that and small claims court, the system has been flawless, including the pan drain with upper-limit switch.
 
To avoid these ads, REGISTER NOW!
Top Bottom