| Heat Number - 1 | |||||
| Lane | Comp.No. | Name | YoB | Club | Time |
| 3 | 1 | Luca HALLAM | 12 | Grantham SC | 3:49.64 |
| 4 | 3 | Francesco MONACO | 12 | South Lincs Competitive SC | 3:12.53 |
| 5 | 2 | Samuel NICHOLS | 12 | Grantham SC | 3:32.46 |
| Heat Number - 2 | |||||
| Lane | Comp.No. | Name | YoB | Club | Time |
| 1 | 5 | William VERE | 09 | South Lincs Competitive SC | 2:50.80 |
| 2 | 7 | Benjamin MORRIS | 09 | Boston Amateur SC | 3:03.76 |
| 3 | 9 | Aaron SADLER | 10 | South Lincs Competitive SC | 2:50.17 |
| 4 | 11 | Oliver SHEPHERD | 09 | Deepings SC | 2:49.28 |
| 5 | 10 | James CASH | 10 | Deepings SC | 2:48.78 |
| 6 | 8 | Matthew TOMPKINSON | 09 | Louth Dolphins SC | 2:59.62 |
| 7 | 6 | Benjamin DERBY | 08 | Lincoln Vulcans SC | 3:01.88 |
| 8 | 4 | Rian SOUTHWOOD | 10 | Louth Dolphins SC | 3:23.27 |
| Heat Number - 3 | |||||
| Lane | Comp.No. | Name | YoB | Club | Time |
| 1 | 13 | Aidan FITZGIBBON | 08 | City of Linc Pentaqua SC | 2:51.14 |
| 2 | 15 | Jacob SOWDEN | 06 | Lincoln Vulcans SC | 2:39.49 |
| 3 | 17 | Matteo MONACO | 09 | South Lincs Competitive SC | 2:39.63 |
| 4 | 19 | Harry KINGSTON | 04 | City of Linc Pentaqua SC | 2:27.68 |
| 5 | 18 | Frank LAMB | 09 | South Lincs Competitive SC | 2:38.79 |
| 6 | 16 | Jacob BRIERS | 08 | Deepings SC | 2:33.96 |
| 7 | 14 | Daniel HEPPLESTONE | 10 | Lincoln Vulcans SC | 2:37.80 |
| 8 | 12 | Zach HOPKINSON | 09 | Grantham SC | 2:45.48 |
| Heat Number - 4 | |||||
| Lane | Comp.No. | Name | YoB | Club | Time |
| 1 | 21 | James NICHOLS | 09 | Grantham SC | 2:30.29 |
| 2 | 23 | Finnley DANBY | 06 | Boston Amateur SC | 2:25.81 |
| 3 | 25 | Owen HATHWAY | 06 | Grantham SC | 2:18.54 |
| 4 | 27 | Rico BRINGEMAN | 05 | South Lincs Competitive SC | 2:07.60 |
| 5 | 26 | Alex SADLER | 07 | South Lincs Competitive SC | 2:20.79 |
| 6 | 24 | Oscar GOLDSMITH | 08 | South Lincs Competitive SC | 2:16.46 |
| 7 | 22 | Thomas HEPPLESTONE | 06 | City of Linc Pentaqua SC | 2:25.52 |
| 8 | 20 | Ryan NORTON | 07 | Boston Amateur SC | 2:31.28 |