EVENT 104 Men 15 Yrs/Over 400m IM - Heats
| Heat Number - 1 |
| Lane | Comp.No. | Name | AaD | Club | Time |
| 3 | 1 | Lucas Granville | 15 | Nova Cent'n | 5:18.20 |
| 4 | 3 | Finlay Gibson | 15 | Co Leicester | 5:12.41 |
| 5 | 2 | Ethan Ford | 16 | Co Leicester | 5:14.00 |
| Heat Number - 2 |
| Lane | Comp.No. | Name | AaD | Club | Time |
| 0 | 7 | Noah Van Hoorebeek | 16 | Chesterfield | 5:06.60 |
| 1 | 13 | Samuel Leveridge | 17 | Calv Bing | 4:59.90 |
| 2 | 19 | Alfie Bisby | 16 | South Lincs | 4:54.41 |
| 3 | 25 | Findlay Cordle | 16 | Repton | 4:48.50 |
| 4 | 31 | Rico Bringeman | 18 | South Lincs | 4:36.41 |
| 5 | 28 | Luke Stevens | 17 | Co Leicester | 4:44.60 |
| 6 | 22 | Joseph Mulligan | 17 | Bramcote | 4:53.00 |
| 7 | 16 | Oliver Oxley | 17 | Co Leicester | 4:58.20 |
| 8 | 10 | Kallum Quirke | 17 | NottmLeander | 5:02.10 |
| 9 | 4 | Oliver Stone | 15 | Ripley | 5:11.45 |
| Heat Number - 3 |
| Lane | Comp.No. | Name | AaD | Club | Time |
| 0 | 8 | Jack Bignell | 15 | Northampton | 5:06.18 |
| 1 | 14 | Harrison Clarke | 15 | Nova Cent'n | 4:59.37 |
| 2 | 20 | James Lake | 16 | Loughborough | 4:53.80 |
| 3 | 26 | Samuel Cooke | 17 | Corby | 4:47.02 |
| 4 | 32 | Thomas White | 21 | Nova Cent'n | 4:36.08 |
| 5 | 29 | Adam Wilson | 20 | Lboro Uni | 4:42.20 |
| 6 | 23 | Paul Page | 16 | Co Leicester | 4:52.90 |
| 7 | 17 | Luke Jeal | 20 | Nova Cent'n | 4:56.90 |
| 8 | 11 | Daniel Harris | 16 | Co Leicester | 5:01.50 |
| 9 | 5 | Sam Gray | 16 | Northampton | 5:11.03 |
| Heat Number - 4 |
| Lane | Comp.No. | Name | AaD | Club | Time |
| 0 | 9 | Manav Mistry | 16 | Northampton | 5:04.44 |
| 1 | 15 | Luke Chambers | 15 | Nova Cent'n | 4:59.00 |
| 2 | 21 | Archie Dandy | 15 | Co Leicester | 4:53.20 |
| 3 | 27 | Alex Keeble | 19 | Leic Sharks | 4:45.00 |
| 4 | 33 | Charles Kershaw | 21 | Lboro Uni | 4:26.40 |
| 5 | 30 | Elliot Sibley | 18 | Nova Cent'n | 4:39.70 |
| 6 | 24 | Daniel Walker | 16 | Nova Cent'n | 4:50.30 |
| 7 | 18 | Oscar Goldsmith | 15 | South Lincs | 4:55.20 |
| 8 | 12 | Owen Hathway | 17 | Grantham | 5:00.62 |
| 9 | 6 | Lewis Fitch | 16 | Co Leicester | 5:08.98 |