The boiler is being installed - it's not there yet, and it won't be until next week at the earliest! Apparently the piping is all wrong, so some of the floorboards have had to come up... what a saga.
The owner of the company I worked for before I was made redundant was known to sue people who left before their official leaving date for breach of contract. But it looks like you'll be well within your rights to leave that place. Good luck in your new job!