Drain/Sewer Vent Issue

[jake7995]

Hello all!

I have been in my house for 10 years, and I’ve recently started noticing issues with the following drains:

Laundry room washer drain:

sewer gas smell

Garage floor drain:

• Sewer gas smell a lot more often than previously experienced from evaporation
• The drain has a 90 that dips into the water level to provide the trap. If I dump water into it quickly, it will siphon the water down below the elbow.

Here is what I’ve done.

Garage Floor Drain:

• Trying to prove it isn’t plugged I ran a garden hose in the drain for 10 minutes at full flow. The drain filled to the top of the drain pipe, but never got higher.
• While filling with a drain hose, I dumped 2 gallons in the drain rapidly, it created a major vacuum and drained faster than with only the hose running. It was like dumping water into a toilet.
• I checked the 3” vent stack from the roof with a camera and didn’t see any plugs. I ran a camera up the drain line from the cleanout and didn’t see any plugs. I am not able to look at the whole line due to elbows, etc which prevent me from pushing the camera through.

Other info:

• There aren’t any issues on the 2 sinks, 2 toilets, bathtub or shower
• If I fill water slowly to the bottom of the garage drain elbow, it will not suck it out, only if I fill far enough for the drain to flow water.

I have attached a schematic of my drain/vent system in my house.

Any help is appreciated...Thanks!

 

[christopherdbrown]

Hello all!

I have been in my house for 10 years, and I’ve recently started noticing issues with the following drains:

Laundry room washer drain:

sewer gas smell

Garage floor drain:

• Sewer gas smell a lot more often than previously experienced from evaporation
• The drain has a 90 that dips into the water level to provide the trap. If I dump water into it quickly, it will siphon the water down below the elbow.

Here is what I’ve done.

Garage Floor Drain:

• Trying to prove it isn’t plugged I ran a garden hose in the drain for 10 minutes at full flow. The drain filled to the top of the drain pipe, but never got higher.
• While filling with a drain hose, I dumped 2 gallons in the drain rapidly, it created a major vacuum and drained faster than with only the hose running. It was like dumping water into a toilet.
• I checked the 3” vent stack from the roof with a camera and didn’t see any plugs. I ran a camera up the drain line from the cleanout and didn’t see any plugs. I am not able to look at the whole line due to elbows, etc which prevent me from pushing the camera through.

Other info:

• There aren’t any issues on the 2 sinks, 2 toilets, bathtub or shower
• If I fill water slowly to the bottom of the garage drain elbow, it will not suck it out, only if I fill far enough for the drain to flow water.

I have attached a schematic of my drain/vent system in my house.
Old homes often come with hidden challenges. Last year, I bought an older house and completely overlooked the gutters, my home inspector missed them too, which was my mistake. After a heavy rain, I noticed water overflowing from the gutters, and it hit me that I hadn’t cleaned or inspected them since moving in. The very next day, I called gouttiere drummondville for help. They came on time, cleaned out the clogged gutters, and even set up a reminder for the next inspection with winter approaching. It’s just one of those common issues you deal with in older homes!

Any help is appreciated...Thanks!

I think the sewer gas smell and siphoning issue are caused by an air pressure imbalance in your drain system. Even though you've checked the vent stack, partial blockages or vent issues further down the line could still be affecting the garage drain. Try using a drain snake to clear any hidden blockages and follow up with water jetting to remove grease.

 

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[Reach4]

You don't show a vent for the laundry standpipe. I am not clear if your code allows AAVs (air admittance valved), but a standpipe could be modified to prevent siphoning. I have thought that a washing machine adds its last water in dribbles, so would refill the trap even if it had siphoned earlier. It could be that you have enough clothes that the trap can dry between uses.

What you illustrate for the floor drain is not what is allowed. Do you have reason to think that floor drain does not have a P-trap?

During winter the humidity drops as air is heated. So traps would dry out more quickly. Some floor drains are built with trap primers that add a bit of water at times to fight the drying.