Did you ever see a 3 pipe or 4 pipe water system? Well, it is more common than you think.
Let's see 3 pipes. What could they be hot, cold, and (hmmmm) warm? Could it be hot, cold, and very cold? That would be nice, wouldn't it. Well, normally it isn't either of those things. Then what about these third or even fourth pipes? Maybe the plumber had some left over pipe (yeah that's it)?
Actually, I find these real common in larger houses 40+ years old. The third and fourth pipes could be several things, but most commonly they are either hot water recirculating lines or well water lines.
If a home is large and the water heating equipment is located far from the end fixture (usually a bath tub or lavatory/bath sink) then an extra line is run back to the water heater to facilitate less time getting hot water to the fixture. If you have to wait 30 seconds or more for the water to turn hot at the faucet you'll appreciate this one.
The third or fourth line (as the case may be) could also be a well water line. Many homes that switched from a well to city water retained the well for outside faucets (sill cocks). Why did they do this? Easy, don't have to pay the city for watering the lawn or washing the car.
If you should see water lines numbering 3 or 4 don't think you can abandon one or two of them, they just might serve a purpose.
Jack Gilleland
Home Inspection Services, Clayton
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