There's a drain pipe that goes down 10 floors on my balcony and there are flies coming out from the drain.

I found very helpful information from this post:
https://www.askmehelpdesk.com/plumbi...es-205451.html
But unfortunately the products (Drain Gel, Microfoam) are not available in the stores in my area. Since my building is quite old I don't feel safe using Draino, would those eco-friendly drain cleaners help get rid of the flies?

Or, I wonder if it would help if I just find something to cover up the drain opening, say a piece of brick?

Thanks a lot.

MicroFoam: Control Fruit Flies, Gnats, Drain Odors is th link to order from or simply close off the drain.
Good luck. Tom

What exactly does the "opening " look like ? Can you snap a photo of it and post it ? Thank you...

Thanks for the link speedball1. But, they don't ship outside of the US (I live in Canada) so no luck for me.

Milo, attached is a picture of the drain opening.

Something I find really weird is that people I've talked to here (in Home Depot and other hardware stores) have never heard of drain flies. One of them told me that flies don't come out of drains. As for closing the drain opening. The rep I talked to today told me to just tape it, I don't know if that would work.

Thanks.

Here's another link that you may find helpful: How to Get Rid of Drain Flies
Good luck, Tom

Another example why I tell folks not to seek advice at any big box store. Follow Tom's link or just dose them with 2 quarts of bleach.

You probably...

1. don't have trap
2. don't have trap primer
3. have dry trap

First, check if there is trap. If positive, keep it wet (filled with water) if not remove the drain cover and insert "Dollar Plug" or "Wing Nut". It will seal it.

Thanks everyone.

speedball1, the link is very informative, looks like some of the suggestions can be applied to outdoor drains as well. Milo, thanks, this is the first time I heard about "dollar plug" and "wing nut", and strange enough the people at the hardware stores asked me what they are. I am going to ask my friends in the US to buy one for me (can't see any trap).

Thanks a lot!


For some reasons I am not allowed to rate all the responses...

Bun,
I t doesn't make difference if there's a trap or not. Drain flies live in the slime above the trap in the raiser. I tried using bleach in my shower with no results.
Would it be possible to seal off the drain? Good luck, Tom

Wun-bun: There may be difference in terminology but I am sure they sell similar product all over.

I am enclosing photo what it looks like. It is a plug used during construction for test purposes during construction. They may not have it in local hardware store but if you go to a plumbing supply store that caters to professionals than I am sure they'll carry it. It may have wings or may be flat.

Make sure you know your size before you go to buy it. First, remove the drain cover and measure I.D. of the opening of the pipe (not the inlet of the drain). Common sizes are 1 1/2", 2", 3" and 4". Then, you install it inside the drain, tighten it and re-mount the cover over it.

Good luck. Let us know how you did. Milo

Thanks again Speedball1 and Milo!

I tried very hard but wasn't able to remove the drain cover, so I asked a plumber to help me with that (there was one in my building to do some other works so I thought I should take advantage of the opportunity). He took a look and suggested that I should make sure that the flies do come from the drain first because the cover is not easy to remove. So I am putting a toilet plunger on top of it for now to see if the flies disappear.

Milo, thanks a lot for the photo. I finally found something similar in a specialty store. People there are much more knowledgeable than the ones I had talked to in the other hardware stores.