Can a bailiff enter my house if no one is in?

No

The bailiff may not enter any domestic property that is locked, and nobody is at home, unless the bailiff is collecting an unpaid court fine,^[1] or money owed to HMRC,^[2][3] where in those circumstances, the bailiff may enter using reasonable force.^[4]

If you leave a door unlocked, the bailiff may enter by opening the door.^[5]

If you leave a window wide open while you are out, the bailiff may not enter through the window.^[5]

^{[1] Paragraph 18(b) of Schedule 12 of the Tribunals, Courts and Enforcement Act 2007
[2] Section 127 of the Finance Act 2008
[3] Paragraph 19(2)(b) of Schedule 12 of the Tribunals, Courts and Enforcement Act 2007
[4] See Bailiffs threatening to break entry using as locksmith
[5] Regulation 20(a) of the Taking Control of Goods Regulations 2013}