Extra plastic tubing out of a utility faucet

[williamson_39]

Hi - I have a basement utility sink with a single faucet assembly with separate hot and cold taps. On the back of the brass faucet body, there is a secondary small male threaded spout. This is connected to some quarter-inch plastic tubing that feeds down through the basement floor beside the sink/washing machine drain, presumably into the main basement drain (like the condensation drain from the a/c). When either the hot or cold taps are turned on, fresh water goes back through this tube as well as out of the main spout. The water lines come down from above, if that matters.

Can anyone tell me what this extra plastic line is for? Even stranger, there is a brass T in the plastic line, and each branch feeds loosely into two different half-inch plastic tubes going down through the concrete floor. Each smaller tube goes several feet into the larger ones, but isn't attached. I can't imagine what this little squirt of fresh water, mixed hot/cold, is doing under there, but the builder apparently spent a lot of time setting all this up....

It's about 8 years old now, and one of the branches must have a slight plug, because when I run the water too fast, I now get some water backing up through one of the mystery tubes. Before I try to clear it, I thought I'd ask why I need this at all. :confused:

Thanks!

Bob

[hj]

It sounds like a "do it yourself" trap primer system to keep the floor drains from losing their water seals. The small tubes have to be "loose" in the larger ones to prevent the possibility of "sucking" the drain water up into the water supply piping.

[williamson_39]

Thanks for the thoughts. My concern was that this faucet actually includes the secondary outlet as a feature - the thing is manufactured for this purpose, but given the rest of the strange setup, I agree it seems like a bit of a hack.

I have enough condensation flow out of the hot water heater and a/c year round to keep the drain wet (a lot more than we'd get from our rare use of the utility sink), but I might as well clean it out and leave it in place.

Thanks!