My A/C unit is pumping sewer gas through my house!

Reply

  #1  
Old 06-26-16, 08:45 PM
A
Member
Thread Starter
Join Date: Jun 2016
Posts: 6
Received 0 Votes on 0 Posts
My A/C unit is pumping sewer gas through my house!

Hello,

I recently bought a 1965 built house that was re-designed in 2008. This is my dream home... but it has a few issues that i found out after-the-fact. I have an independent 3 ton AC unit and a 4 ton blower in my home. Im located in NC, and so the AC unit also has a heat pump cause it rarely gets cold. My A/C unit is located right next to my septic tank. The septic tank was recently replaced and new drainage fields were put in. The outside smells like septic, but it isnt that bad. My house spells TERRIBLE. The AC is pumping in sewer. And smells MUCH MUCH worse than outside (in fact, i can hardly smell anything outside at this time).

My attic smells GREAT! Which blows my mind. This is a mystery to me, and im not the brightest tool in the shed when it comes to this stuff. Learning as i go.

My roof has 2 pipes located at each end of the house where my bathrooms are. I think these are my exhaust fans for the bathrooms right? But that is it. Isnt there supposed to be intake pipes on the roof for my septic?

I thought that the house stank because the septic was 40 years old. That is fixed. Then only the bathroom next to the ac unit stank and my logic was that the ac unit was sucking up the septic smell from the outside and pushing that air up next to the bathroom window (the AC unit is 2 feet from my house and my septic is 2 feet from the AC unit; 4 feet from the house). But now i dont know what to think! Its 11pm and my house has never smelled this bad. Any help would be appreciated.
 
Sponsored Links
  #2  
Old 06-26-16, 10:04 PM
Houston204's Avatar
Forum Topic Moderator
Join Date: Oct 2009
Location: Texas
Posts: 7,425
Received 17 Votes on 14 Posts
It sounds like you need to install a P-trap in the AC drain.


 
  #3  
Old 06-26-16, 10:16 PM
PJmax's Avatar
Group Moderator
Join Date: Oct 2012
Location: Northern NJ - USA
Posts: 59,805
Received 1,194 Votes on 1,105 Posts
This problem was posted in three different threads thoroughly confusing the replies.

I posted this in one of the other threads before I deleted it....

I'm sensing a lot of confusion here.

A split heat pump has the condensor unit outside and the air handler (blower) inside. The two are connected with refrigerant lines. No air is exchanged between the two units. No air is brought in from the outside.

It is possible that your air handler has a vent line to outside to allow fresh air to be brought into the system. That would be a rare occurrence.

The pipes on the roof should be approx 1-1/2" to 2" in diameter and would be vent pipes for the plumbing.

The ductwork for the bathroom fans should be 3"-4" in diameter and if they go thru the roof they usually use short caps or hoods on them. The duct wouldn't be sticking up out of the roof and be in plain sight.

Do you have an attic fan ? That could possibly bring in smelly air from outside.
Where is the air handler in the house ?

I hadn't considered the air handler drain being directly and incorrectly connected to the septic system.
 
  #4  
Old 06-27-16, 06:05 AM
A
Member
Thread Starter
Join Date: Jun 2016
Posts: 6
Received 0 Votes on 0 Posts
Hi PJ,

Yes, im a little confused . So the AC unit doesnt take the smell from the outside ?

- I'll need to check where the air handler is located.

The only vents i see are 2 septic vents on the roof (and i was up there walking around haha). That is it. I wonder where the exhaust vents for my bathrooms are going? Do i need to go into the attic to locate them?

My attic smells great. Im not sure if there is a fan or not, but i didnt notice one when i was in there yesterday. I'll do another pass through after work tonight. Thanks.
 
  #5  
Old 06-27-16, 06:31 AM
Bob14525's Avatar
Member
Join Date: Jun 2013
Location: USA
Posts: 1,596
Received 26 Votes on 21 Posts
Pete is correct, the only connection between the A/C outside unit and the inside unit are the refrigerant lines (no air is exchanged between the two units). The evaporator ("cold coil" located inside your air handler) causes the hot moist air to condense (much like a dehumidifier). All air handlers with an A/C component (evaporator coil) have a condensate drain (usually 1" PVC piping). You will have to locate the condensate drain pipe coming off your air handler and see what it's draining into. If it's draining into your septic system, that could be the reason for the smell in the house. Since the condensate drain is connected to the air handler, any odors that come into the condensate pipe can get pumped throughout the house by means of the blower in the air handler. That is why Houston suggested that you install a P-trap in the condensate drain. The P-trap functions much like the trap in a sink drain. By keeping a small supply of water in the pipe, it blocks sewer gases from coming back up the open drain.
 
  #6  
Old 06-27-16, 12:25 PM
Houston204's Avatar
Forum Topic Moderator
Join Date: Oct 2009
Location: Texas
Posts: 7,425
Received 17 Votes on 14 Posts
Heat pumps are usually matched with air handlers.
Most air handlers have the evaporator coil on the negative pressure side of the blower. Without a p-trap the air handler can pull sewer gases into the house.
 
  #7  
Old 06-27-16, 01:59 PM
pugsl's Avatar
Forum Topic Moderator
Join Date: Mar 2008
Location: United States
Posts: 9,029
Received 74 Votes on 67 Posts
The only thing I would add to what Pete said is if you have a combined unit that all components are outside. evaporator and condenser are in a big box outside. It would be connected to house with duct work. I only have seen a few of these but I live in NC also. If this is the case outside air could be drawn in.
 
  #8  
Old 06-27-16, 08:07 PM
A
Member
Thread Starter
Join Date: Jun 2016
Posts: 6
Received 0 Votes on 0 Posts
Great suggestions!

Yes, the air handler is next to my blower and is connected via pvc pipe. It has a J trap, but it looks kinda shallow. That is the angle is not as deep compared to something under a sink. Is that ok? Should i get a J trap that is more steep or would that trap the condensate water from the blower?

Another development, the wife put glade plug ins in the bathroom where it was stinking. We walked into the home today and the whole house smelled like a glade plugin. So perhaps my entire issue is coming down to a failed toilet seal?

Cheers
 
  #9  
Old 06-27-16, 09:09 PM
crabjoe's Avatar
Member
Join Date: Apr 2004
Location: USA
Posts: 299
Received 0 Votes on 0 Posts
Another development, the wife put glade plug ins in the bathroom where it was stinking. We walked into the home today and the whole house smelled like a glade plugin. So perhaps my entire issue is coming down to a failed toilet seal?
I don't see how a wax ring would cause it, but odder things have happened.

But I do have a question... You don't by chance have a return in your bathroom do you? If you do, get rid of it... Also make sure you bathroom vent .. not the AC vent, but the went to rid the stink is being blow out of the house...

I find it very strange your glade plug in is not covering you whole house.
 
  #10  
Old 06-27-16, 09:47 PM
A
Member
Thread Starter
Join Date: Jun 2016
Posts: 6
Received 0 Votes on 0 Posts
I have a return right outside the stinking bathroom that is connected to the blower. I have closed off that bathroom completely for weeks now. I have been running the fan in the bathroom 24/7. But im not exactly sure where that goes... cause it does not go straight out of the roof. Sounds like something i need to go attic crawling for.

"I find it very strange your glade plug in is not covering you whole house."

The glade plug in IS covering the whole house. Which is strange. Since the bathroom is closed off from the return. Again, im not sure what is the science is. I'll keep you guys posted. Im set to replace the seal tomorrow.
 
  #11  
Old 06-28-16, 05:32 AM
crabjoe's Avatar
Member
Join Date: Apr 2004
Location: USA
Posts: 299
Received 0 Votes on 0 Posts
BIG Oops on "I find it very strange your glade plug in is not covering you whole house."

That that NOT should have been "NOW" ...

"I find it very strange your glade plug in is NOW covering you whole house."

Sorry.. I fat finger it and it changed the complete meaning.
 
  #12  
Old 06-28-16, 09:01 PM
A
Member
Thread Starter
Join Date: Jun 2016
Posts: 6
Received 0 Votes on 0 Posts
Removed the toilet... no wax. The right side of the steel flange was completely rusted to dust. So I installed a new wax steal and bolts; and after some close calls, got that toilet put back on. I need to take it back off this weekend as the bolt to the right is literally not connecting the toilet to anything. Need to get a Grab flange for that side. I am now officially a plumber XD

I'll keep you guys posted how the house smells. Incredibly after taking off that toilet, the house does not smell bad at all. Luckily it isnt hot outside so the AC isnt cycling that crap air through the house.

Cheers
 
  #13  
Old 06-28-16, 09:15 PM
A
Member
Thread Starter
Join Date: Jun 2016
Posts: 6
Received 0 Votes on 0 Posts
actually i probably should replace that flang. What flang should i use?
 
  #14  
Old 06-28-16, 10:58 PM
PJmax's Avatar
Group Moderator
Join Date: Oct 2012
Location: Northern NJ - USA
Posts: 59,805
Received 1,194 Votes on 1,105 Posts
That would be flange.

We'd need to see a picture of what you have to advise you on a replacement.
They come in cast, PVC, brass. It depends on the type of drain line.

http://www.doityourself.com/forum/el...-pictures.html
 
Reply
Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off


Thread Tools
Search this Thread
 
Ask a Question
Question Title:
Description:
Your question will be posted in: