EVENT 304 Mens Open 400m IM - Heats
| Heat Number - 1 |
| Lane | Comp.No. | Name | AaD | Club/Country | Time |
| 3 | 1 | James Watson | 17 | Plymouth Lea | 4:41.45 |
| 4 | 3 | Caleb Mackey | 18 | Grantham | 4:40.91 |
| 5 | 2 | Alfie Kelly | 16 | Newcastle | 4:41.35 |
| Heat Number - 2 |
| Lane | Comp.No. | Name | AaD | Club/Country | Time |
| 1 | 5 | Euan Cowan | 17 | York City | 4:40.20 |
| 2 | 7 | Richard Mawson | 18 | Co Leeds | 4:39.57 |
| 3 | 9 | Oliver O'Halleron | 17 | Derwentside | 4:39.43 |
| 4 | 11 | Michael Rees | 17 | Sutton Cheam | 4:38.32 |
| 5 | 10 | Marcus Dey | 16 | Co Salford | 4:39.13 |
| 6 | 8 | Matthew George | 17 | Co Salford | 4:39.53 |
| 7 | 6 | Fraser Allison | 17 | Warrender Ba | 4:39.66 |
| 8 | 4 | Adam Brown | 18 | Millfield | 4:40.72 |
| Heat Number - 3 |
| Lane | Comp.No. | Name | AaD | Club/Country | Time |
| 1 | 13 | Ben Harrison | 17 | Mt Kelly | 4:38.05 |
| 2 | 15 | Jakob Goodman | 17 | Millfield | 4:36.40 |
| 3 | 17 | Joel Thompson | 16 | Shiverers | 4:35.96 |
| 4 | 19 | Kieran Wheatley | 18 | Co Derby | 4:35.56 |
| 5 | 18 | Myles Stirk | 17 | Co Leeds | 4:35.94 |
| 6 | 16 | Ryan Retson | 17 | F.I.R.S.T. | 4:36.40 |
| 7 | 14 | Adam Wilson | 16 | Newcastle | 4:37.44 |
| 8 | 12 | Tony-Joe Trett Oliver | 18 | Mt Kelly | 4:38.26 |
| Heat Number - 4 |
| Lane | Comp.No. | Name | AaD | Club/Country | Time |
| 1 | 21 | Max Jameson | 17 | Thanet Swim | 4:34.87 |
| 2 | 23 | Rubens King | 20 | Portsmouth N | 4:33.97 |
| 3 | 25 | Nathan Wells | 19 | Loughboro Un | 4:32.98 |
| 4 | 27 | Matthew Domville | 20 | Warrington W | 4:31.10 |
| 5 | 26 | Charlie Hutchison | 15 | Ellesmere Co | 4:31.15 |
| 6 | 24 | Zak Logue | 19 | Co Sund'land | 4:33.26 |
| 7 | 22 | Archie Goodburn | 16 | Warrender Ba | 4:34.00 |
| 8 | 20 | Ryan Brown | 19 | Co Glasgow | 4:34.90 |
| Heat Number - 5 |
| Lane | Comp.No. | Name | AaD | Club/Country | Time |
| 1 | 30 | Craig Munden | 20 | Loughboro Un | 4:30.75 |
| 2 | 34 | John Britton | 22 | Ealing | 4:25.68 |
| 3 | 38 | Thomas Paine | 23 | Co Manch Aq | 4:22.91 |
| 4 | 42 | Richard Nagy | 24 | Co Sheffield | 4:13.87 |
| 5 | 40 | Fraser Minnican | 22 | Loughboro Un | 4:20.11 |
| 6 | 36 | Nathan Hughes | 17 | Loughboro Un | 4:23.36 |
| 7 | 32 | Callum Lawrie | 19 | UniOfStirl | 4:27.91 |
| 8 | 28 | Alastair Miley | 23 | Aberdeen Per | 4:30.96 |
| Heat Number - 6 |
| Lane | Comp.No. | Name | AaD | Club/Country | Time |
| 1 | 31 | George Clough | 18 | Warrender Ba | 4:30.30 |
| 2 | 35 | Jacob Greenow | 18 | TauntonDeane | 4:24.49 |
| 3 | 39 | Joe Litchfield | 19 | Co Sheffield | 4:22.51 |
| 4 | 43 | Max Litchfield | 22 | Co Sheffield | 4:11.62 |
| 5 | 41 | Mark Szaranek | 22 | Edinburgh Un | 4:17.61 |
| 6 | 37 | Brodie Williams | 18 | Millfield | 4:22.95 |
| 7 | 33 | Thomas Dean | 17 | Maidenhead | 4:27.41 |
| 8 | 29 | Joseph Miley | 20 | Aberdeen Per | 4:30.78 |