I've Lost Wireless Connection to Printer

[BeeS4335]

I have a Macbook Air and a HP Photosmart C4380 printer and both worked fine wirelessly until I had to replace my BT Home Hub. Now I cannot get the MBA to connect wirelessly to the printer - I try to print and nothing happens. When I connect the computer to the printer with a USB cable it does work but since there is only one USB port on the MBA I really want to restore the wireless connectivity. I suspect it's just a matter of reconfiguring something but I simply don't know what. The printer manual is hopeless about the Mac - just says something about LAN settings. Can anyone help me? In case it matters, I'm in the UK. By the way, the computer connects OK through the replacement home hub wirelessly using Airport.