Fixtures
Also described as "fixtures and fittings", these are items such as radiators and light fittings which are deemed to be part of the property.
Generally speaking, if something is screwed in, nailed down or plumbed in it will be regarded as a fixture and left in the property. Be aware there are exceptions, so you should make sure that what you think are fixtures really are - otherwise you might find they're not there when you move in to your new home!
Fixtures should be included in the sale unless specifically excluded in the contract (as opposed to chattels). The person carrying out your conveyance should handle this.