Trying to get one of the hoses off my thermostat and it's stuck solid. Anyone got any tips how to get it off?

screw driver down the sides just give it a lil push then when it feels like hose has come loose yank it of with a up and down action. THis is assuming you have removed the jubilies.

brute force (often followed by regret)

Used a combination of the two techniques and it came off Spent an hour cleaning the thermostatwith vinegar and an old toothbrush (couldn't find a big bottle of vinegar lol) and then popped it into a pot of water and brought it to the boil.
Thankfully, as soon as the water showed signs of coming to the boil the thermostat closed! Well chuffed! That saved me £50.