If I was renting my house out and there was an accidental fire, will the insurance deny my claim?
I was renting to a tenant and didnt notify the insurance company(allstate) that I was renting. There was a fire and now they are saying that they wont pay for it because I didnt notify them. Can I fight this? and whats the best way?

You lose.
You can’t use homeowner insurance for business purposes. All they have to do is refund your premium.
Yes, they can deny the claim because you didn’t have the proper coverage.
It is a change in material risk. The langue in the contract is such that this will be able to get them off the claim. You should have notified the insurance company. You will now pay for it.
HOMEOWNERS insurance, is for owner occupied homes.
You weren’t living in your house. The policy is invalid.
You’re not going to win.
The WAY to fight it, is by hiring a lawyer. But to put it in other terms, it’s like going to McDonalds, and paying for a Big Mac, and getting upset because they didn’t give you a pizza.
I think your homeowners policy does cover your rental property regardless of whether you have tenants or not. This must be a pretty cheesy insurance company if they wont cover a fire. I never heard of that.