Gurgling floor drain - sump pit - radon fan - Help!!

Old 11-16-18, 05:05 PM
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Gurgling floor drain - sump pit - radon fan - Help!!

I'm a pretty mechanical/DIY capable guy, but this one has me stumped.

The situation: House built in 1966 (Wisconsin). My basement floor drain has emitted a gurgling sound since I bought the house a few months ago.The floor drain has a Dranjer drain seal installed. Below that appears to be some type of ball float mechanism, but the ball is destroyed and I can't removed any of it due to corrosion. Upon investigation I have discovered several things. First, the floor drain appears to just drain straight through the concrete into the ground/drain tile, not the sewer line. Those drain tiles of course drain into my sump pit. My sump pit is sealed air tight, with a radon pipe going just under the clear plastic cover. I discovered that when I turn off the radon fan, the gurgling stops. A stream of water also starts entering the floor drain from the sidewall when the fan is stopped. There is a pipe tapped into the sidewall for the humidifier drain, but the water comes from just below the pipe.

So does anybody know what I'm dealing with here? Are these components all setup the way they were supposed to be? If so, what can I do to stop the gurgling noise? I'd like to finish the basement this winter and the sound will drive me insane.

Thank you for any help.

Video of the drain gurgling:

Video with the radon fan off:
Old 11-17-18, 12:44 PM
Join Date: Feb 2001
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The drain seal is a FloodGuard made by General Specialties. It is designed to be removable. There is an expanding rubber gasket around the outside that is pushed outward by tightening the set screws. Loosen those set screws and you should be able to remove it. you may need to wrench it out as it looks like it has been in there for a while. "The radon pipe goes just under the clear plastic cover". Not quite sure what you mean by that. Where does the radon fan discharge to? If the sump is a sealed chamber and the radon piping runs underneath your slab and is tied into your footing system, then the gurgling noise might be air being pulled through the floor drain into your footing system, then out through the radon fan. Drop some peppermint oil down the floor drain, run the radon fan for a few minutes with the lid on then open the lid and see if the sump is super pepperminty. That would confirm the relationship. Do you need that floor drain? It appears to be on carpet, which is never a good mix. You may consider abandoning this drain and permanently sealing it. You would then need to weigh the cost and risk of doing so if you were to ever have a flood. Any other floor drains in the basement? A drain tied into the sanitary plumbing waste system shouldn't have the gurgling problem as it is a completely separate system.

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