I’m very happy for you in your made up home, but central heating and plumbing and requirements for construction where I live.
It is definitely more a part of the house than an appliance in that it is built into the house during it’s construction by the builders. Ranges are not the same as indoor plumbing, are you sure you’re a builder? You can add and remove walls after the fact too but it doesn’t make them an accessory in the sense that you are trying to claim.