Vax pressure washer inline fuse

[robins]

Good morning all,
I have a 2500W Vax pressure washer, almost 3 years old, but only light summer use, could be described 'as new'. Pressure washing the decking the other day, Mrs wanted to cut the hedge so I let her use the long decent quality outdoor extension, I used a short indoor extension instead, shortly after the pressure washer stopped working, no drama, just stopped.
yes, I now know, two mistakes - inappropriate extension cable and 2 high draw appliances on the same circuit. Upshot - blown internal in line fuse, marked 13A 250V but only a small 20mm x 5mm cartridge fuse.
Vax wont help, out of warranty, wont supply and don't have info on internal parts!
Nearest fuse I can find is 12.5A on farnell.com but various choices on what I assume is the max load rating, from 125A upwards. Which one do I need?
Thanks for reading, I hope someone can help, don't want to take Vax's offer of 'a deal on a new one' just for a replacement fuse!

Hi Dean, did you find a supply I have the same problem