Here is a sample BOM (Bill of Materials) a contractor would try to purchase on a website:
| Item | Description | Qty |
| 1 | 1/2" copper pipe - 10' | 30 |
| 2 | 1/2" copper 90 | 60 |
| 3 | 1/2" union | 12 |
| 4 | 1/2" copper tee | 10 |
| 5 | 3/4" copper pipe - 10' | 6 |
| 6 | 3/4" copper 90 | 10 |
| 7 | 3/4"x 1/2" tee | 2 |
| 8 | 75 gallon AO Smith 75K BTU water heater | 1 |
| 9 | WH flexible lines | 2 |
| 10 | Water heater pan | 1 |
| 11 | 1/2" PEX - red - 300' roll | 1 |
| 12 | 1/2" PEX - blue - 300' roll | 1 |
| 13 | 1/2" PEX crimp rings | 100 |
| 14 | 1/2" copper sweat to 1/2" PEX | 2 |
| 15 | 1/2" PEX elbows | 30 |
| 16 | 1/2" PEX Tees | 15 |
| 17 | 3/4" copper sweat ball valve | 4 |
| 18 | 1/2" PEX/copper stub outs | 12 |
| 19 | 1/2" bell hangers | 40 |
| 20 | 3/4" bell hangers | 20 |