# Interesting problem



## 422 plumber (Jul 31, 2008)

Got an emergency call to one of the schools I take care of. The 3" domestic RPZ is in full dump mode. The 4" floor drain right under it is backing up and water is flooding into the gym. The maintenance boss calls me and says we might have a "show stopper" if it continues. Dismissing students during the day causes major problems, parents gotta leave work, the school doesn't get money from the state, bad news. I get there within a hour and flip the discs on the checks and bang, problem solved. I vacuum the water out of the floor drain and discover the p-trap is full of cement. I chip out around the nearby c/o and pull the c/o body off the riser and install a tee and run over and stick a trap under the domestic dump and the fire main RPZ dump. Get a call today, the domestic rpz is in full dump, but it's dumping into the trap, so school isn't affected. My idea is to install lazy hand pressure gauges so I can see if it's pressure spikes causing it, because the school is about 1/4 mile from a huge city water tank. The rpz is dumping a small stream, and i shut off the inlet valve and the dump valve gushes! How is this possible with the water off? Maybe there is crossover at a mop faucet, because Chicago faucets are notorious for bad cartridges causing crossover, especially on a recirc system. I go to the recirc piping, and it's cold coming back into the heater! What the hell! I start changing the mop faucet cartridges, and discover: the faucet farthest away doesn't get hot, the faucet in the middle works fine, the faucet nearest the mech. room has hot and cold crossed! Hooray for me! This school is 3 years old and why it took this long for the rpz to start dumping, I don't know. I do know that the maintenance boss loves me. At his previous school district I solved a toilet flushing problem that had plagued the school for 6 years. I discovered a 3" main valve in the ceiling, that fed 4 bathrooms, was only open about 1 turn. Opened it up and that solved the flushing problem. He had several other plumbers in, and none of them figured it out, first time he calls me, we were walking the valves down together and there it was. I have been his fairhaired boy ever since. He went to a bigger district, took me with him and I am still solving all his problems. Overtime Friday night for Uncle Jeffie and my partner. It will make up for Monday being a holiday! I will post the rest of the story when the job is done.


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## para1 (Jun 17, 2008)

*Excellent!! *I love it when something so simple does so much. That's an important lesson.


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