Including hifi on general house insurance is possible - itemise each piece of equipment. break down cost of record player into motor unit, arm and power supply if applicable (otherwise you may come up against value limit on individual items).
Mind you, I would be interested if there is any advice on vinyl insurance - taking in to account "value" of "rare"/first pressings
Edit: not hifi, but I put a claim in for a dent I put in to a fairly new fridge freezer by accident (only a couple of months old). I only found out that cosmetic damage wasn't covered when I phoned to find out (page 9, section c, subsection 2d...... you get the idea). Person on the phone agreed that the policy was a bit limited - read all policy notes very carefully.
LP12, Ittok (black), DV10X5, NVA Phono 2 (twin supply), NVAP50, Art Audio Quintet 15w power amp, NVA LS5 cable, Rega Ela mk1's.
Sony CDP XB930.