Why is there "sand" in the pipes?

October 11, 2010 11:55 AM

Plumbing puzzle: my neighbor has what looks like find sand which collects in her *hot water* eventually clogging metal screens on faucets, etc. The obvious answer is that this is some sort of mineral precipitate as the system has been flushed several times and a filter installed on the water coming into the house. What is causing this precipitate in the hot water and why doesn't this happen with my hot water which is the same town water on the same street (same pipes) that is going into her house?

Also, the water heater is from tank heated by a closed loop off the hot water furnace. The problem was occuring before this water heater was installed.

posted by ennui.bz to Home & Garden (10 answers total)

Is the house heated by hotwater or steam ? sounds like it could be some kind of rust . Maybe the boiler from the heat itself has to be replaced?
posted by majortom1981 at 11:57 AM on October 11, 2010

There may be differences in the ages and types of piping that each home uses to connect to the municipal water system. I tend to have a worse problem in one of my baths than the other because the bath with the problem still has a few runs of iron pipe that lead to it and the other bath has pex the whole way (ductile iron pipe connects my house to the main in the street).
posted by pappy at 12:09 PM on October 11, 2010

It is possible that someone removed the anode from her water heater. This is there to inhibit corrosion. If it is removed, bits of corrosion materials can travel throughout the hot water system.
posted by Old Geezer at 12:17 PM on October 11, 2010

You don't necessarily have the same pipes. Galvanized steel pipes are notorious for corrosion, and could be the source of the problem. Your house might have had the service connection (pipes from the main to the house) or the interior plumbing upgrade to copper or PVC at some point. Is she experiencing low water pressure as well?

The other answers upthread are also worth looking into.
posted by electroboy at 12:22 PM on October 11, 2010

I had the same problem, or at least a similar one. It was caused by a plastic "pickup" pipe inside the water heater that was disintegrating. We didn't have any more problems after we replaced the water heater.
posted by 14580 at 12:48 PM on October 11, 2010

Sounds like the Sacrificial Anode Rod has been removed. This rod prevents rust but can sometimes introduce the smell of sulfur into hot water. Removing the rod will stop the smell but slowly destroy the water heater. Check if the rod is missing or completely used up.
posted by reeddavid at 12:49 PM on October 11, 2010

Is her hot water heater turned up too high? Could be boiler scale forming and flaking off. It's more likely to be corrosion products, like everyone else is saying, though.
posted by ctmf at 1:14 PM on October 11, 2010

Response by poster: the water is heated by the furnace, which was just replaced < 9 months ago.... maybe the tank doesn't have an anode, i will check.
posted by ennui.bz at 1:44 PM on October 11, 2010

Best answer: Calcium carbonate is less soluble in hot water than in cold. If your neighbor has considerably hotter water than you that is one explanation.

I'd see if the fine sand dissolves in a couple of acids (vinegar, citric acid or hydrochloric (muriatic) acid if you have it). If it dissolves and your water is known to be hard, this might be the problem.
posted by jet_silver at 4:15 PM on October 11, 2010

This happened to me. The hot water holding temperature is set too high. Turn it down and the problem should go away.
posted by Mr.Me at 8:02 PM on October 11, 2010