Clog at back flow device

located inside a residential garage.
The cleanout is in the garage, located in a 2x2 by 3 deep field (cement casing). The backflow device is located about 12" behind the cleanout. The house is backed up and there is sewage water coming out of the backflow cap. The cleanout is bone dry. I can run hose water through the cleanout w/out a problem.

Has anybody tackled a problem like this? What did you do?

I meant backwater valve

Sorry about that!

If there is no C/O anywhere in the house then you will have to pull a toilet and snake through that or go up on the roof and down through the vent if you have one big enough.

What?

Read the post, there is a cleanout, but the backwater valve is before it (on the house side). If I snake, I'll hit the backwater valve. Do I want to do that? Prob not.

Is the backwater valve on the house side of the C/O or the street side?

sewer

If you snake the line, be sure to remove the backwater valve's cap and hold the gate open when you remove the snake, or you will damage the backwater valve, and possilby the snake also. You really don't have any good option other than to remove the cap of the backwater valve and clean it out there. However, the BWV's cover should be downstream of the flapper, so I cannot imagine what could have plugged it up.

Piece o'cake...

The blockage was at the backflow valve as suspected. I had to shape the end of a 4' section of 3" ABS to match the cap. I drilled a hole in the top of the ABS so I could insert a handle. With that I was able to remove the cap and flapper. The house drained out immediately. Cleaned & replaced the flapper. Replaced the cap and viola, happy Customer.

I bought a bunch of these 3 and 4" backwater valves about 9 years ago for pennies on the dollar and I can't even get pennies on the dollar off any online auctions.

I've ran cables through them only to find out AFTER the fact they was buried outside with no access.

Well, that's what the camera showed afterwards.


So easily a strand of toilet paper or some gradual feces buildup can hang that flapper open......or better yet, the rubber on the flapper warps and doesn't hold back the river of sewage waiting to enter the basement. Look out!