[rurumomee]

I just had a piece of the dryer duct (the part that goes from house wall to outside) replaced by a plumber (he was working on repiping our gas leak and also took care of this repair). The previous part was a flexible one with a big crack in the middle, so all the lint (as well as the air) was escaping.

In the evening after the repair work, I ran the washer and dryer (I have a stackable unit in the kitchen) and about 10-15 minutes after the dryer started, we noticed a very strong musty wood smell in the house. Oddly we can't detect the smell near the dryer. It's most noticeable in the bathroom, which is behind the dryer (the dryer resides against the wall that is shared with the bathroom), and especially in the bedroom that is on the other side of the bathroom.

The dryer duct fix has definitely helped with the laundry drying quality and I can tell that the air being exhausted to the outside is much stronger and hotter. It's just bizarre that the repair has brought on this strange odor issue. Please help!

[hkstroud]

Quite likely that there was build up of lint in the duct work between the point where the dryer is connected and the outside. This would be caused by ruptured section between the dryer and the wall connection due to a lack of air volume and speed.

Now that the ruptured section has been repair the build up of lint is restricting the air flow and it, or part of it, is being forced out the joints of the duct work inside the wall. Have to find a way to clean duct work.

[mygirlsdad77]

I would make sure the plumber didn't tie the dryer vent into the bathroom exhaust fan vent. Ive seen it way to many times.

[rurumomee]

Hello. Is there a way I can tell if he did this? I'd rather not have to call him back again . We had a disagreement at the end of the job.

[hkstroud]

Tell us exactly what work he did.

[rurumomee]

Thank you for your quick responses. I actually scheduled a vent cleaner for next week, but on the phone he seemed doubtful that the cleaning would help the smell because we can't smell it near the duct inside the house (FYI the connection goes from back of the dryer, runs up and along the kitchen ceiling (housed within cupboards) and to the wall. The plumber fixed the part from the wall on and did not touch any of the duct inside the house.

What I'm most worried about is that the now much hotter air is causing something to surface into the air (something bad meaning mold or dead rodent)...

[rurumomee]

Here is what the plumber did, and sorry I'm a complete layman so I can't talk shop:

1) He replaced the house gas pipeline, part of which runs behind our water heater. FYI our water heater sits outside the house but housed in a little wooden "shack".

2) In the process of replacing the pipe, he had to disconnect and pull out the water heater. During this work, he noticed the dryer vent hose running above the water heater and that it had a big crack. He also noticed that the flue next to the dryer hose wasn't secured properly, and warned me that if it incurred damage by falling ,etc, I would have an asbestos problem.

3) As a result, he replaced the cracked hose (which was a flexible white one) with an aluminum one. He also removed the flue (he told me we don't need it).

4) I didn't watch over the work, and I can't compare with what it looked like before the repair, but now the dryer duct/hose comes from the house wall, then forks out, with the horizontal duct exhausting outside (out of the water heater shack) and the vertical duct going up and out of the top of the shack.

[hkstroud]

but now the dryer duct/hose comes from the house wall, then forks out, with the horizontal duct exhausting outside (out of the water heater shack) and the vertical duct going up and out of the top of the shack.

That make no sense. You would not split a dryer exhaust vent. You would simply vent it to one place.

I would have an asbestos problem.

With out further information that is questionable.



Apparently you don't know what the flue going through the roof is or was for?

Am I correct that the vent through the roof is the same as the flue he removed?

Implication is that you have a gas water heater. Is it properly vented?

Can you post pictures?

[rurumomee]

Hello,
Please find the pictures attached.
Picture 1: Water heater shack (you can see the dryer exhaust to outside)
Picture 2: Inside shack (sorry I was totally off on my description. Water heater vent, which used to include the asbestos flue, is on its own)
Picture 3: Close-up of dryer duct. Only the left one is used and is the newly replaced one.
Picture 4: Dryer duct coming in from outside.
Picture 5: Duct continuing through the kitchen.
Picture 6: Duct continuing through and running down to back of dryer.
Picture 7: Dryer position (not much clearance in the back, but that is where the flex hose is, which will be replaced by vent cleaner next week)
Picture 8: Showing layout of the bedroom (with window visible), bathroom, then dryer. You can see there's also a wall furnace on the wall between the kitchen/dryer and bathroom.

[hkstroud]

Show picture of water heater shack roof and side of house above?

Agree dryer duct inside the house is not likely to be the problem. Cleaning is not likely to be productive.

I have several questions, like where is the chimney for the furnace, what is the duct on the right for if the dryer vent is on the left.

The white flexible material used to connect the water heater looks like vinyl. If so that is not acceptable for that use. I know of no flexible material acceptable for that use but I could be wrong.

What I suspect as this point is that the vent on the right is a bath fan exhaust, the vent on the left is the dryer exhaust as you have said, and the flexible material used to connect the water heater flue is vinyl dryer hose and is what is causing the odor.

[rurumomee]

Hello,
Thanks for staying on this issue. I took photos from the roof.
1. Picture 1: The flex duct you pointed out seems to be made of metal. I hit it and it is hard; it's not plastic.
2. Picture 2: The smaller roof vent (between the other two) in fact resides right around where the smell is. Below that vent area is the wall that separates the dryer and the bathroom, and along that wall is also the wall furnace. When I press against the wall furnace, I can smell the odor, though it's not as strong as in the bedroom.

We don't use that particular furnace because when the pilot light is on, it's just too noisy.

I guess it's something within this particular vent, and I guess it's somehow connected to the dryer?

[hkstroud]

I see no indication that the dryer exhaust vent is cross connected to any thing.

The smaller vent (on the roof next to the furnace flue) will be your plumbing vent. Not sure that it is with in code being that close to the furnace flue. It is possible that the sewer gasses from the sewer vent are being drawn back down the furnace flue if the furnace is not being used. That might explain the odor in the wall next to the furnace. The odor could travel to the bedroom through the heating duct. Have no logical explanation for why you would notice this after repairing dryer exhaust pipe. Perhaps coincidence.

I see nothing wrong with the dryer exhaust repair.

The code in your area probably requires that the water heater flu either be insulated or be the "B" vent gas type flue. "B" vent type flue is a double walled type flue pipe. What the plumber removed was probably single wall and insulated. That insulation would not have been asbestos. It is obvious that the house is not old enough for it to have been asbestos. The water heater flu repairs are pretty rinky dink and certainly not professional. Working with "B" vent is not the easiest for the novice because it cannot be cut to required length like regular single wall flu piping. Proper lengths and turns must be purchased. This is not something you will normally find at Home Depot or Lowe's. However, I believe that flexible "B" vent flue is available from heating suppliers

Because it is out in the open and not close to any thing combustible this is not something to panic over but should be address by someone knowledgeable, perhaps a heating tech.

I would not have expected a sewer gas odor to have been described as a "very strong musty wood smell".

Would the odor be better described as a the smell of sewage?

Sniff around the furnace and around the heating vents of the bedroom.

When you smell the odor, turn the furnace on and see if the odor goes away.

P.S.
While looking at the water heater I noticed that the electrical system grounding wire appears to be connected to the hot water pipe. It should be connected to the cold water pipe.

P.S. to the P.S.
It has just occurred to me that when you are using the dryer you are blowing air out of the house.
For air to go out the dryer vent, air must come in from some where. If the house is very tight the only place may be the furnace flue. Perhaps that is why you are drawing sewer gas in (if it is sewer gas). You might try opening a window while using the dryer and see if you get the odor.

[rurumomee]

Hello,

My responses to some of your queries:

-> Would the odor be better described as a the smell of sewage?

Response: My sons and I all agree that it smells of wet wood (like in an old sauna), not sewage.

-> While looking at the water heater I noticed that the electrical system grounding wire appears to be connected to the hot water pipe. It should be connected to the cold water pipe.

Response: Uh oh... but how can a licensed plumber make this kind of mistake? What does it mean? Is this dangerous?

-> If the house is very tight the only place may be the furnace flue. Perhaps that is why you are drawing sewer gas in (if it is sewer gas). You might try opening a window while using the dryer and see if you get the odor.

Response: Actually both times I ran the dryer, I had most windows open but we could still smell the odor in that general area behind the dryer.

I'm going to run the dryer again tomorrow with the windows closed to see where the odor is most concentrated.

Thanks again for all your help.

[hkstroud]

While looking at the water heater I noticed that the electrical system grounding wire appears to be connected to the hot water pipe. It should be connected to the cold water pipe

Would not be something the plumber touched. Probably was done by the electrician when house was built.
Electrician was probably there before water heater was installed and didn't check to see which pipe was hot and which pipe was cold, or just made a mistake. Not a over powering thing. Just should be corrected.

If you get odor with windows open it is not likely to be sewer gas being drawn but just to make sure try running furnace while running dryer. That way we will know. Sewer gas can't come in if furnace is blowing air out.

While running dryer go out side and smell air coming out vent to see if it smell like the odor. Is there any odor in the cabinets when dryer is running? Do you feel any air coming out the duct inside the cabinets when dryer is running?

[rurumomee]

Hello,
I ran the dryer today with all windows closed to see where the smells are. After running it for 15 minutes, I smell it most in the top corner of the bedroom, which is across the room from the window and closest to the "area" in question (the back of dryer - wall - furnace - bathroom - wall - bedroom).

I looked up there and took photos of that area. FYI our house is a pseudo-Eichler type. You can see there is this big rather open area right under the ceiling, and I noticed that there is a metal duct way at the back. I don't know where this comes from or where it goes to. I have a feeling that the smell is either coming from that duct, or from the cracks/gaps in this general ceiling area.

I also smell the odor somewhat from the bathroom ceiling vent and the wall furnace, but the smell is definitely most concentrated in the bedroom.

I think my action plan now is to: 1) Have dryer vent cleaned by the cleaner; 2) if that doesn't do anything, find a contractor to come take a look.

Thanks again for your help.

[hkstroud]

Can't tell what the first photo is. The second must be the space above the ceiling of the furnace area. The duct that you see would be the furnace flue.

With all the things we have considered I think my next step would be to pull the washer/dryer out and look behind it and its connection to the exhaust duct. That should not be unduly difficult but requires a certain amount of physical strength. Should be able to unhook the exhaust vent in the cabinet above and pull the washer dryer out.

[rurumomee]

Thanks for the latest suggestion. It's hard for me to handle that myself so I'll wait for the vent cleaner people to do this and see what happens. I'll post again with an update then. Thanks again for all your help.

[Handyman2007]

I have to go along with hkstroud here. That flex pipe is NOT rated for any high heat purpose. It actually looks like a piece of vinyl dryer vent hose. That definitely would case an odor and will probably melt. That is a 'cob job" if I ever saw one. You should call that guy back... don;t know what the riff was about but this is unacceptable.

[mygirlsdad77]

Handy, see post #11. That's a pre-formed metal vent 90 and is approved for single wall installation. I would question the tape they used though, it may be causing a bit of smell. We are only allowed to use that tape for sealing ductwork, not gas vents in my area.

[Handyman2007]

I am sorry, it looked like vinyl in the other photos. I am not sure about using the metal tape either but it is not combustible but I would worry about the adhesive drying out.