Why do I have 3 copper pipes in my gas water heater? It seems two are cold and one is hot. All videos I see online show only two pipes; one for cold coming in, one for hot going out.
Depending on the specific system installation and type of tank it could be any of these:
Cold in, hot out, and overflow: Standard water heater.
Cold in, hot out, recirculate in. This configuration has diverse uses:
- typical for a solar water heating booster.
- In heavy use applications, it could be for an external hot water reservoir.
- In long lines applications, this could be for recirculating hot water so that a faucet 400 feet away has hot water available just a few feet away. Many motels and hotels are plumbed this way.