Council Tax - you might get a rebate/reduction in payments as no-one is actually living there. Also, let your your local community Police Officer know the house isn't technically occupied, they'll keep an eye open.
i am currently living in my mother's home, but have a home of my own. She has moved to a care home but I have to be close by, as she needs a lot of one to one. But presumably I have to pay council tax for mum's home too? I had got her the dementia exemption but it was just before she went into care.