We moved into an old house, has a bad smell.The gas man came, not that.The smell only comes when heat is on.?

Question

Our house was built in 1898, the smell is almost sewage smell but the septic was new in '99 and I called the septic cleaners and they said that the problem that I am having is not the septic. The smell is coming from the basement but only when the heat is on. We checked all the vents but they are clear and the gas guy said that it is not the gas. Please help!!!!

Answer 1

The smell could be coming from mold growing in the concrete of the walls and floor of the basement. Sometimes that mold will also get into heating ducts and grow there. There are companies that will clean and deodorize the ducts. If you do have that done, you also need to disinfect the concrete walls and floor with a weak bleach solution or anything that is designed to kill mold.

To prevent the return of the mold, you need to be sure there is no excess water getting to the foundation of the house from the outside. The first step here is to extend the outputs of your downspouts five feet or more away from the house. Put a dehumidifier in the basement. That may be sufficient. If not, then it's time to call in a basement repair company.

I live in an old house, too. I've been most of the way down this road. So far I've not had to call in the basement repair folks. I do spray down the walls with disinfectant a couple of times a year.

Good luck!

Answer 2

There are not a lot of possiblities here if it is only when the furnace is on. If it is forced air, check for dead animals or old food in the ductwork. If it is electric baseboard type, try to track down which one generates the smell. One last possibility is that your septic and plumbing system is vented, normally thru the roof. We had an old house that was vented in the attic and didn't realize. It only smelled like a sewer when the air was damp and heavy and the wind blew a certain way. It smelled like the sewer was backing up. Have a similar problem now and even thou the drains have a vent that does go thru the roof, some idiot added a bathroom and chose to add another vent as well and it only vents in the attic. When the wind blows from the north it goes right through the peak vents and blows it back in the house. NOT pleasant.

Answer 3

The house I grew up in used to get bad smells out of the heater ducts from time to time. In that case it was because the house was not rodent-proofed (it was old and basically couldn't be made rodent-proof) and from time to time a mouse or rat would get into the ducting and with no food or water would eventually die and make a stink similar to what you describe.

There are services that specialize in cleaning heating ducting and at least the contractor I used was very good. In a house that old it might be a good thing in general anyways, the ducting has likely collected a lot of dust and debris and dust bunnies and so on.

It might also be that you have water and/or dust bunnies and so on collected somewhere in a duct or the furnace or some other place where it collects material and moisture and grows mold and etc. Then when the system is on and the gunk is heated, it throws off moisture and odors.

Answer 4

I had a similar problem...I hope you're not squeamish.


We had this horrific smell coming from my daughter's room at the beginning of the fall, when the heat started being used again. We tried everything to figure out what it was. It turns out that the heating duct goes inside the wall in her closet, and a bird had found its way into the eaves and got trapped between the walls. Unfortunately, the poor bird perished, and the heat from the duct accompanied by the smell of the rotten carcass was pretty strong.
Our house is about that old, and I'm sure there are plenty of places for critters to get in and out, and they "nest" in places that are warm. Basements are probably easy to get into, since they aren't traversed as often by people, and the occasional hole in the wall, or gap in the door goes unnoticed.
I have also heard that sometimes birds will perch atop the chimney, and the fumes from gasses emitted there cause them to "black out" and fall in...and a narrow chimney is a difficult place for a bird to fly out of.
If you can try to find the poor birdie and remove him, that's great...otherwise, you'll just have to wait a week (give or take) for the body to completely decompose.
If you go about five or so days and the smell gets worse, or doesn't diminish at all...then it could be something else. But, since both the gas guy and the septic guy have been there already, I'm not sure what else it could be....maybe mold.
Good Luck!

Answer 5

You'll probably want to hire this one out. How old is the furnace? Do you have refrigerated air (A/C)? Whatever the age, check the heat exchanger for deterioration and blower fan housing for gunk and mold. Check the A/C coil for the same gunk and mold. That's the likely culprit. Check the A/C condenser drain trap for blockage, which would cause the condensate water while running the A/C to pool at the coil, which would feed mold and smelly gunk. A professional duct cleaning company would help here a lot. While you're at it, have them clean all the duct work. Over a century of dust and dirt in the air handler system couldn't smell all that great anyway! Hope that helps!

Answer 6

Could be that the problem originates in the basement--when the heat comes on it 'cooks' the area and draws the smell through the house. Check ALL the pipes to make sure you don't have a leak. Also, there are products out there to spray around to eliminate odors (not those flowery things--check at the local hardware store and ask for a product that eliminates the smell from a wet basement).

Answer 7

I had the same problem with my house. I finally had the filter replaced and the ducts and the furnace cleaned. This helped immensely. Another option is to spray down a heavy duty mold-mildew cleaner in the basement, after this is done place a very strong dehumidifier in the basement with the drainage going into the main drain. This will hopefully remove your odor.

Answer 8

If you have a sink, shower or any floor drain in the basement that doesn't get used very often, you can get what is called a "dry trap". Without any water in the trap you can get sewer gas backing up into your home. If this only happens when you run your furnace you may not have enough combustion(out side) air, assuming you have a gas fired furnace/boiler. Try adding water to the floor drain. If this works check into a combustion air intake for your furnace. Just a thought. Thanks

Answer 9

It is the mold. This is nearly impossible to fix, sorry. Old houses get wet and they mold. The only way to fix it is to take out all the mold or seal everything under primer and paint but who paints duct systems?

The sellers could be responsible in this case. In many home sales....owners must disclose health risks...if they did not then you may have recourse. Mold is definitely a health problem.

If you want to keep the house, it is going to take work. You have to clean or paint every surface in the house.I have heard of a system where they cover the house and poison everything but I am not sure of the system or even if this is a good idea.

As the asmatic mother of 2 asmatic kids I wish you very good luck!

Answer 10

Check the filter and the heating element(s) in your furnace... they may have build up or some sort of residue on them that burns off when it heats up..... also you might want to have the airducts cleaned.... you might have a dead rodent or something in there that smells and the smell drifts out either as it is warmed up as the heat circulates or by the blower as it forces the air through the vents. Certain molds or mildews may also have a smell that comes through as the furnace cycles.