08:21PM | 05/09/05
Member Since: 05/08/05
3 lifetime posts
Hi, I REALLY need advice from experienced people. Recently, there is very bad smell coming from our first floor air return. Although I never really smelled of dead animals, it smells like a dead rat somehow to me. The smell is very strong at about 10:00pm and get milder in the day time. The air retun is in the hall way between the bath room and the living room. The other side of the wall is garage. The smell is also in the garage and the two bed rooms above. I suspect that there is a dead rat, since a couple days before the smell came, we heard rats in the wall and trapped a roof rat. However, I also suspect that there might be some plumbing leakage causing mold or mildew in the duct, since I dont understand that why the smell is strong in the evening. The only reason I have is that my parents in law take shower before bed which is around 9:00pm and their bath room is above the first floor bath room which is near the air return. I have talked to the air duct cleaning people. However before I would spend several hundreds dollars on it, I would like to know whether I should hire a plumber to detect any leakage first. PLEASE, you suggestions and comments are highly appreciated.


08:25PM | 05/11/05
Member Since: 08/29/04
227 lifetime posts
It could be possible that the shower drain is allowing sewer gas to come back into the house and the return air is drawing it back into the heating system. If there is no water in the trap of the shower (or there is no trap) then the sewer gas will be sucked right into the return of the heating system. This can happen if the door is closed and the room draws a vacuum, because of the return air. But most bathrooms don't have return air grills in them, exactly for that reason. In addition return air grills in bathrooms draw in moist air into the duct work, which can develop mold from the dark and moisture. This doesn't sound to me like a properly designed system. I'm wondering who installed it.

Good Luck

Raymond VinZant Plumbing Prof.


12:28PM | 05/24/05
Member Since: 05/08/05
3 lifetime posts
Thank you, Ray, for your reply. The smell is better now. I hired a plumber to check the leak. When he was at my house, it is morning and there is no any smell. He checked the water pressure gauge and there is no movement, so he concluded that there is no leakage and not likely the sewer gas, since he did not smell any. These two days the smell is less stink, but still there around 10:00pm.

BTW, the retun air grill is not in the bath room. There is a air vent in the bath room.



Post a reply as Anonymous

Photo must be in JPG, GIF or PNG format and less than 5MB.


type the code from the image


Post_new_button or Login_button

Pursue what's known as the stack effect. To achieve it, open the windows on both the upper and lower floors, and as warm a... Reused steel windows create an eye-catching splashguard in this walk-in shower. The vintage factory windows bring an inter... A galvanized steel tub is a surprising but charming fixture in this bright and breezy screened patio. It's perfect for was... If you're not crazy about the idea of commingling plants and pool, this modern variation may be more to your liking. The s... Yes, a freestanding garage can become its own tiny house. Artist Michelle de la Vega has all the comforts of a modern resi... If you lack plumbing skills but have a good sturdy tree, here's the easiest outdoor shower solution of all: Simply attach... Need a window and a door in a tight space? A Dutch door with a window may be your answer. These useful doors are split hor... How do you like this smart use for an old bottle? Clamp an empty wine bottle to a fence or wall near your outdoor deck or ... Simple and striking, a couple of pieces of "lovingly used" furniture creates a special kind of charm. A weathered chair fo... Twine lanterns add pops of crafty—but sophisticated—flair to any outdoor setting. Wrap glue-soaked twine around a balloon ... When securely fastened to a tree or the ceiling of a porch, a pallet and some cushioning make the ideal place to lounge. V... Incorporate nature into your lighting scheme by securing a dead tree in a concrete mold and draping your pendant lamp from... For the cost of a can of exterior paint , you can totally transform your porch. Paint the floor a hue that complements yo... Repurpose birthday hats to create a string of lanterns for your porch, patio, or garden. Cut the tip of the cone, punch h... This garden shed has been decked out to the nines. Designer Orla Kiely created the intimate home for a flower trade show, ...
Newsletter_icon Google_plus Facebook Twitter Pinterest Youtube Rss_icon