Piping an expansion tank onto a water heater involves connecting it to the cold water inlet line, typically using a tee fitting and a short length of pipe. Here's how to do it:
1. Location and Preparation:
- The expansion tank is usually installed on the cold water inlet line to the water heater. This location allows it to effectively absorb pressure fluctuations.
- Ensure the water heater is turned off and the cold water supply is shut off before you begin. Drain a small amount of water from the water heater to relieve pressure.
2. Tee Fitting Installation:
- A tee fitting is required to connect the expansion tank to the cold water line. This fitting diverts a portion of the cold water supply to the expansion tank.
- If no tee fitting exists: Cut into the cold water supply pipe above the water heater. Install the tee fitting, ensuring it's properly secured with either solder (for copper pipes) or appropriate fittings for other pipe materials like PEX.
3. Connecting the Expansion Tank:
- Short Pipe Section: Using either sweat-soldering or push-fit connections, attach a short length of horizontal copper pipe—no more than six inches long—to the tee-fitting's side outlet.
- Adapter: Attach a female threaded adapter to the horizontal pipe using your preferred connection method. This adapter will mate with the male threads on the expansion tank.
- Attach the Tank: Screw the expansion tank onto the female threaded adapter. Hand-tighten it, then use a wrench to give it an additional half-turn to ensure a secure and leak-proof connection.
4. Support (if needed):
- Large expansion tanks might require support to prevent strain on the piping. Use hangers or straps to secure the tank to a nearby wall or ceiling joist.
5. Charging the Tank:
- Before turning the water supply back on, check the pre-charge pressure of the expansion tank. It should ideally match the static water pressure in your home. You can adjust the pressure using a Schrader valve (like a tire valve) located on the tank.
6. Testing for Leaks:
- Slowly turn the cold water supply back on.
- Carefully inspect all connections for leaks. If any leaks are found, tighten the connections or re-do the connections as needed.
In Summary: The process involves installing a tee fitting on the cold water inlet, attaching a short pipe section and adapter, connecting the expansion tank, and ensuring proper support and pressure settings to manage water pressure fluctuations and protect your water heater system.
