| B Final | |||||
| Lane | Comp.No. | Name | AaD | Club/Country | Time |
| 0 | 1 | Max Tambling | 18 | Hackney | 4:03.37 |
| 1 | 2 | Craig Munden | 20 | Loughboro Un | 4:02.26 |
| 2 | 3 | Kieran Bird | 18 | Millfield | 4:01.82 |
| 3 | 4 | Samuel Osborne | 16 | Co Birm'ham | 4:01.49 |
| 4 | 5 | Max Murphy | 17 | Co Milton K | 4:00.76 |
| 5 | 6 | Regan Lloyd | 20 | teamipswich | 4:00.98 |
| 6 | 7 | Thomas Howley | 21 | Newcastle | 4:01.56 |
| 7 | 8 | Nathan Hughes | 17 | Hatfield | 4:02.10 |
| 8 | 9 | Ross Hill | 20 | Loughboro Un | 4:02.70 |
| 9 | 10 | Harry Constantine | 17 | Hatfield | 4:03.82 |