Mysterious white plastic debris plugging faucets
Posted by Craig Erickson on May 05, 2004 at 12:19:28:
Sorry for the long post, but want to give all the info I can so maybe someone can diagnose this puzzling problem.

My home was built in 1966, it's got copper supply piping. The laundry faucet is the type with lever handles on horizontal shafts, so you lift up both hot and cold handles to turn on. The harder you'd turn on the hot water, the slower it would flow! No problem with laundry tub cold water flow.

Today I found pieces of white plastic debris which is responsible for partly plugging water flow at hot side of laundry tub faucet. Found the debris when disassembling the faucets to investigate problem. Now that I think about it, the first time I found such debris was at kitchen sink about 4-5 years ago, so this is not a new problem.

At that time, there were a couple chunks of plastic the size of your little fingernail (but thicker) stuck just below the Moen cartridge in the kitchen faucet. Today there were half a dozen similar chunks stuck in the laundry faucet body just upstream from the faucet washer of the hot water side. The biggest chunk was 3/4" long and almost 1/2" wide. The thickness is uniformly about 0.050", and both sides are smooth.

The pieces of plastic are all curved hinting they may once have been part of a pipe with a diameter approx. 1/2" ID. The curvature of these chunks matches the curvature of a AA penlight battery if that helps you envision them. I could email a photo if that would help. Each chunk has craze marks showing that it's tending to crack apart further. The plastic is white and fairly hard and shiny. If you bend it, you can tear it apart further on the craze marks.

It's a thermoplastic because it melts when a soldering iron tip is put against it. I don't think it's PVC because it doesn't soften when soaked in acetone.

I have called our water Dept. and they claim it can't be anything from their system. Not sure I believe them, but what more can I do on that angle?

I have lived in the house for 33 years. I replaced the original AO Smith 40 gal. natural gas water heater in 1984 (when the heater was 17 yrs old). The replacement heater installed at that time is still in service, making it now 20 yrs old. It is a Thermar Homemaster Deluxe tankless 100,000 btu natural gas fired model.

This heater has only required one repair in those 20 years. 5 years ago I replaced the rubber diaphragm which senses pressure drop to turn on the mechanical gas valve when hot water is called for. The heater is operating just as good now as when it was new.

Is it possible this white plastic debris is coming from something in the Thermar heater which is disintegrating? I am doubting this theory because the heater is still working fine, but I'm at my wit's end trying to think of any other cause. I don't think the street pressure reducer has any plastic like that inside, do you? The water meter was replaced within the past 4 years.

Any ideas you could give would be welcome, thanks!