| Heat Number - 1 | |||||
| Lane | Comp.No. | Name | AaD | Club | Time |
| 3 | 1 | Luca HALLAM | 11 | Grantham | 3:49.64 |
| 4 | 2 | Fabian KOLASA | 12 | Grantham | 3:47.38 |
| 5 | 3 | Stanley THURLOW | 10 | Lincoln Vulc | 3:40.00 |
| Heat Number - 2 | |||||
| Lane | Comp.No. | Name | AaD | Club | Time |
| 1 | 4 | Oscar DURANT | 12 | Grantham | 3:37.93 |
| 2 | 6 | Oliver SHEPHERD | 13 | Deepings | 2:49.28 |
| 3 | 8 | Jacob BRIERS | 15 | Deepings | 2:33.96 |
| 4 | 10 | Thomas HEPPLESTONE | 17 | Co Lincoln P | 2:25.52 |
| 5 | 9 | Harry KINGSTON | 18 | Co Lincoln P | 2:26.86 |
| 6 | 7 | Zach HOPKINSON | 14 | Grantham | 2:45.48 |
| 7 | 5 | Samuel NICHOLS | 11 | Grantham | 3:32.46 |