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What could this horrible chemical smell coming from the laundry room? Could it be plumbing? Answered

I just bought this money pit of a house....I had this horrible smell coming from the laundry room. I bought new appliances and as soon as they removed the old ones the smell was gone. The new ones are hooked up and the smell seems to have returned. It's not as strong as it was before, but it's back none the less. I was hoping that the smell went with the washer but sadly it has not...I am wondering if it could be something in the drain? If it were the pipes wouldn't the entire house smell each time I used the water??


trying checking the anode rod in your water heater. look this up as this is a common problem. simple fix.

If you place the vent in a wall you'll need to make sure there is sufficient air flow to allow the vent to open properly. The best thing to do if you put the vent in a wall is to install a return air vent grill at the quick vent level. That way it will get adequate air flow and if necessary, you can replace it if it fails.


6 years ago

Hi everyone! Thank you for all of your replies! The house is 36 years old, I believe that the laundry room used to be apart of the garage, it's a townhouse, not too many options on where to install the appliances. There is no ventilation in there. I know that the smell isn't coming from the garage either. There is no sink, not sure how they've done it to be honest. It is really difficult to describe the smell. It isn't gas, I have had a gas guy, an electrician and a plumber in the room to check it out. The smell is just chemical, it's gross and very difficult to describe as I have never smelt anything like it. The washer and dryer are brand new front loaders, only used once (twice including a rinse load w/vinigar). The previous machines were probably as old as the house, thus why I blamed them and like I said, once they were removed the smell went wtih it until I did a load of laundry. The plumber said that it wasn't a gas smell, but he couldn't tell what it was. I had an air freshener in there, apparently that was all he could smell. I have done a load with vinigar hoping that would do the trick, sadly, it has not. I am at my witts end and am not sure who to call in next...maybe a priest to exercise this house! Now I have a gasoline smell coming from an air vent in the bedroom that is above the garage. The insanity does not stop around here!

How old is the house? Where is the laundry room located? What type of odor do you smell?

Many times in older houses, laundry facilities were an addition to the original plumbing system and were not properly vented. When water is discharged down the drain, it creates a vacuum behind the draining water column. This vacuum can suck the trap dry and thereby allow sewer gas to enter into the room. Another possible cause is the same situation in a floor drain. If the laundry room is near the furnace and/or water heater you could be getting gas from a dry floor drain trap. Floor drains can become dry over time through evaporation or also by the above mentioned vacuum action. Priming the drain periodically with a glass of water can help.

If, you are getting a sulfur or rotten egg smell it’s most likely a gas leak. This should be dealt with immediately. Turn off the gas, shut off all ignition sources, ventilate the room, and call the gas company or a plumber.

If it is a funky fungus type of odor, it could be coming from your washer as Re-design mentioned. There are treatments for that condition.

You may also have a dead rodent, mold, or other odor source. It's hard to diagnose without more information.


Our last house had similar problems. It was built in the 1940's and had funky plumbing (funky everything, actually). There were always bad smells drifting up from the pipes. If you have a septic tank and failing drainfield rather than being hooked up to sewer line, the nasty gas in the tank gets displaced by incoming wastewater and will form a stinky cloud over your house. This is most noticeable when you run a week's worth of laundry in one day.

We ran into the dried-out drain issue (mentioned by diyoutdoorsman) at two labs I've worked at. Be sure to check for any drain you may have overlooked. Did the previous owner remove a sink and fail to properly cap the plumbing?

Have you tried a quick vent? They can be purchased at most DIY centers and hardware stores and are very easy to install. They are basically a one-way spring valve that opens by the suction created during the draining process. After the suction is relieved, the valve closes and prevents sewer gas from escaping. They come in various sizes and can be installed indoors in lieu of a vent pipe through the roof. All you have to do is cut a vent pipe into the drain and extend it above the highest water level of the system. Install a female adapter at the top of the vent that matches the size of your quick vent and screw in the vent. It can be installed under a sink or above the stand pipe of your laundry drain. They only cost about $10 and will help prevent dry traps.

Is your washer a high efficiency (HE) washer? If so then that might be the problem. HE washers develop odors when used with certain waters. Tide makes a product just for fixing this problem.

I've noticed the same thing with these HE washing machines. They are great, except for the fact that they're expensive, they stink, and they don't seem to get clothes as clean as regular washers. The manufacturer said that the door to the washer should remain open when it is not in use (to allow it to dry out). Even doing this, the machine seems to develop a mildew smell over time. What we finally did to solve the smell issue was run a load through every so often with bleach. That seemed to solve the smell problem.

It's..It's... Arrrrghhhhh...... to late.

In general damp, poor ventilation and spillage are the man causes of smells. Solve them and you solve the smell.

Assuming there isn't a leaking package of ACME industrial solvent stashed somewhere.

Describe the "chemical smell" ?


Yes, we need to know what it smells like in order to give you more specific feedback. Does it smell like ammonia, rotten eggs, sewage?


6 years ago

Check the vent from the roof. If the drain is poorly vented it could cause the p-trap to suck dry... causing you to smell sewer gases.

Open the various hatches and drawers of your appliances.

Is there a black or slimy build-up? Sniff in there - is the smell strongest in there?

If so, pull out what parts you can and scrub clean with hot water, maybe a touch of disinfectant.