wrote in message
ups.com...
. I'm seeing small black
rocks{charcoal,rust?} floating around in the toilet. They get under the
rubber seal in the fill valve preventing it from shutting off. It
flushes fine a couple of times and then keeps running. Now my wife did
open up the safety valve on the water heater, which she shouldn't have.

There are a couple of possibilities. Do you have a well? It could be bits
of sand picked up by the pump. If so, they will probably show up in the
other faucet aerators. Check them to be sure. Even with city water you can
get some grit. The cure is a filter for particulates.

The hot water flush should not affect the toilet at all, but strange things
do happen. The sudden release from the valve may have caused a little water
hammer and released the particles that have been clinging in the pipes for
years.

With city water, the water dept. often do a hydrant flush once or twice a
year. When they do that in my neighborhood, I have to change the filter the
next day. Could it be that your wife was that being done and inspired her
to do the water heater? That would explain a lot.
--
Ed
http://pages.cthome.net/edhome/