EVENT 138 Open/Male 15 /Over 400m Freestyle - Heats
| Heat Number - 1 |
| Lane | Comp.No. | Name | AaD | Club | Time |
| 1 | 1 | Samuel Cooper | 15 | Long Eaton | 5:22.70 |
| 2 | 3 | James Missin | 15 | DerbyPhoenix | 5:11.80 |
| 3 | 5 | Danny Barron | 16 | Etwall | 4:59.70 |
| 4 | 7 | Henry Jones | 15 | Dronfield | 4:56.00 |
| 5 | 6 | Joseph Cooper | 18 | Long Eaton | 4:59.30 |
| 6 | 4 | Ethelbert Hems Gillson | 16 | Repton | 5:09.70 |
| 7 | 2 | Ryan Bullock | 15 | Long Eaton | 5:12.80 |
| Heat Number - 2 |
| Lane | Comp.No. | Name | AaD | Club | Time |
| 0 | 9 | Lucas Kimber | 15 | Derby Excel | 4:50.30 |
| 1 | 11 | Joseph Lauda | 15 | Repton | 4:45.30 |
| 2 | 13 | Cole Webster | 17 | BelperMarlin | 4:44.47 |
| 3 | 15 | Aaron Johnson | 18 | Repton | 4:40.46 |
| 4 | 17 | Jack Harris | 15 | Derby Excel | 4:38.00 |
| 5 | 16 | Evan Johnson | 15 | BelperMarlin | 4:38.70 |
| 6 | 14 | Carlos Sierra Villegas | 16 | Chesterfield | 4:42.50 |
| 7 | 12 | Billy Harding | 15 | Repton | 4:44.60 |
| 8 | 10 | Thomas Townsend | 15 | Repton | 4:49.70 |
| 9 | 8 | Zachary Stephenson | 17 | Repton | 4:50.50 |
| Heat Number - 3 |
| Lane | Comp.No. | Name | AaD | Club | Time |
| 0 | 19 | Harry Milne | 16 | Repton | 4:33.30 |
| 1 | 21 | Reuben Hubinger | 15 | Repton | 4:29.03 |
| 2 | 23 | Dylan Jamieson | 16 | Derby Excel | 4:22.90 |
| 3 | 25 | Findlay Cordle | 17 | Repton | 4:12.00 |
| 4 | 27 | Alexander Harrand | 19 | Long Eaton | 4:04.14 |
| 5 | 26 | Thomas Wilkinson | 18 | Chesterfield | 4:07.56 |
| 6 | 24 | Noah Van Hoorebeek | 17 | Chesterfield | 4:22.00 |
| 7 | 22 | Jacob Pemberton | 15 | BelperMarlin | 4:25.10 |
| 8 | 20 | James Ralph | 17 | Buxton | 4:31.70 |
| 9 | 18 | Martin Iankov | 16 | Repton | 4:33.40 |