Odor under kitchen sink in Island

[dkoaustin10]

Hello -

Looking for some advice. We purchased our new construction home in December of 2017. Since first moving In we noticed an odor under the kitchen sink- sometimes its worse/stronger. It doesn’t seem to be coming from the drain above - it’s really prevalent under the sink cabinet.

We’ve had the plumbers, dishwashing guys, builder, etc out here. They done smoke tests, sealed more around pipes, tore out a wall in our island to seal where the pipe goes into the foundation, etc. The dishwasher doesn’t smell nor does the drain line from the dishwasher to the disposal. We ran the cleaning tablets in the dishwasher and have also done the lemon, ice, baking soda/vinegar, etc cleanings for the sink/disposal.

Given they haven’t been able to resolve, their response is now that they are closing out the warranty as there’s no issues found. Unfortunately there’s still an odor when we open the kitchen cabinet and sometimes more obvious in the kitchen (we think it’s related to when we run the dishwasher and there’s a lot of water going through the pipes).

The sink is installed in an island and I’ve attached some pictures of what it looks like in case that’s helpful. From what I’ve read it could be an issue w/ venting perhaps?

Looking for any advice/guidance - thank you in advance.

 

[Plumber69]

Maybe dead mouse or rat. They can smell for awhile. Maybe its the fire extinguisher

 

[Sponsor]

 

[Cacher_Chick]

If the odor is in the cabinet, the drain and vent piping needs to be exposed for inspection. It may be that one of the pipe joints is bad.

 

[Reach4]

Where is the AAV? Is it behind an access panel on the other side of the island?

I presume the smoke test was negative. How about a peppermint test? In that, a peppermint oil solution is poured into a roof vent by somebody who does not come inside. If you don't then smell peppermint, its not the plumbing leaking the smell.

Can most people pick up on the smell, or just a few sensitive noses?

I'll go with a workman ditched his leftover lunch in there because walking 30 ft to the garbage can was inconvenient.

 

[dkoaustin10]

The smoke test the first time had a bunch of smoke coming in - they sealed and the 2nd time we were good. They did break open the back of the cabinet a few months ago - we found all sorts of garbage (leftover lunches) and random other stuff in there - vacuumed it all out and they sealed the space where the plumbing pipe heads down into the foundation - that seemed to lessen the odor, but it didn't completely get rid of it.

Most people can smell something but nobody quite knows what it is and it's definitely stronger sometimes than others. The plumbers have said they can't smell it, but he also said he's a smoker so his nose isn't great.

 

[dkoaustin10]

For the Peppermint suggestion - How would we know which vent in the roof is the one connected to the kitchen sink? Also, given the sink is in the island - how would they attach that to a roof vent? undergroun?

 

[Reach4]

For the Peppermint suggestion - How would we know which vent in the roof is the one connected to the kitchen sink? Also, given the sink is in the island - how would they attach that to a roof vent? undergroun?

The vents connect to the drain pipes. So the thought is that the smell would go through drain pipes. Since you have an AAV for the island, it does not connect to the vent.

If you picked one vent pipe, I would be thinking to pick one farther from the sewer line exit. But if there are 3 vent pipes, you could have the peppermint oil plus hot water poured into each.

I think a roofer would be a good choice for that part of the job. I think bringing in some children (young noses are more sensitive to smells) to aid in the sniffing would be good.

Or train the dog. Play hide the toy in a different house, but have the toy treated with a very dilute peppermint smell. You want your house to be peppermint-free for the test.

However you may have eliminated the plumbing leak sources. The peppermint test could confirm that, however.

I am not a plumber.

 

[hj]

The second cleanout next to the drain system implies that is a "loop/yoke vent", NOT an AAV. Nothing in the photos shows anything that could allow an odor to escape into the cabinet, so we are as stumped as the people who were there checking it.

 

[Reach4]

Also, maybe stop using insecticide around there for a while. Maybe the bugs can consume the eggs and sardines that were dumped below the island.

 

[Cacher_Chick]

The vents connect to the drain pipes. So the thought is that the smell would go through drain pipes. Since you have an AAV for the island, it does not connect to the vent.

I dont see an AAV- do you?

 

[Reach4]

I dont see an AAV- do you?

Nope. Your and hj's observations are on point.

 

[RebT]

Any solution to this problem? We have a similar issue

Hello -

Looking for some advice. We purchased our new construction home in December of 2017. Since first moving In we noticed an odor under the kitchen sink- sometimes its worse/stronger. It doesn’t seem to be coming from the drain above - it’s really prevalent under the sink cabinet.

We’ve had the plumbers, dishwashing guys, builder, etc out here. They done smoke tests, sealed more around pipes, tore out a wall in our island to seal where the pipe goes into the foundation, etc. The dishwasher doesn’t smell nor does the drain line from the dishwasher to the disposal. We ran the cleaning tablets in the dishwasher and have also done the lemon, ice, baking soda/vinegar, etc cleanings for the sink/disposal.

Given they haven’t been able to resolve, their response is now that they are closing out the warranty as there’s no issues found. Unfortunately there’s still an odor when we open the kitchen cabinet and sometimes more obvious in the kitchen (we think it’s related to when we run the dishwasher and there’s a lot of water going through the pipes).

The sink is installed in an island and I’ve attached some pictures of what it looks like in case that’s helpful. From what I’ve read it could be an issue w/ venting perhaps?

Looking for any advice/guidance - thank you in advance.

 

[Terry]

My first though looking at the cleanout locations was that it was plumbed as and Island Vent.
Someone mentioned mouse. My mom's home the mice chewed the dishwasher drain hose under the unit. In the hall bathroom there were mice in the walls. They're not real careful about where they pee. I found that out when I pulled out all the drywall, blocked it all up and painted Zerolac on everything to seal away the smells.

 

[Reach4]

Any solution to this problem? We have a similar issue

Similar in that you have no visible AAV and you have no visible island vent, and your p-trap trap arm goes through the back of the cabinet?

Can you look at the other side of the back of the cabinet?

 

[WorthFlorida]

The cabinets are pretty well closed up. There seems to be no gaps anywhere except under the escutcheons around the pipes. Since the back of the cabinet was opened and everyone is sure that all joints were glued, especially at the loop vent joints it's a hard call. After two years the outgassing of the cabinets should have stopped by now but you may never know. The two panels above the cabinet doors usually are held in with spring clips. From the backside just push on the panel and remove them. Keep them off for a few days see if the odor permeates into the room.

Another possibility is what is stored under the cabinet. It's usually everything chemical in nature and a poison control center of sorts. Have you ever kept this cabinet empty?

When the back wall was removed and you cleaned out the trash, were you able to see all the way to the kick plate that nothing is there?

 

[Kreemoweet]

May not be an issue with the plumbing at all. Lots of construction materials can be smelly, especially when
applied by the hands of the uninstructed or uncaring. I recall one job where fiberglass and resin was used to
patch one outside area, and a gross excess of the curing agent (methyl ethyl ketone) was used, and probably
dumped on the ground. I could smell that area years later everytime I walked by the house. Countertop/sink
installers sometimes use very stinky stuff to mount the sink or "patch" a less-than-perfect countertop.

 

[WorthFlorida]

May not be an issue with the plumbing at all. Lots of construction materials can be smelly, especially when applied by the hands of the uninstructed or uncaring. I recall one job where fiberglass and resin was used to patch one outside area, and a gross excess of the curing agent (methyl ethyl ketone) was used, and probably dumped on the ground. I could smell that area years later everytime I walked by the house. Countertop/sink installers sometimes use very stinky stuff to mount the sink or "patch" a less-than-perfect countertop.

Not long ago my undermount kitchen sink detached from the granite top. The ding dongs used construction adhesive instead of silicone to attach the sink with only two brackets instead of six. .