Hello @Ciaran49 ,
Let me share a thought with you. When a stay is very budget-friendly, these kinds of issues can sometimes happen because when guests save money, the host is often cutting costs too. Sometimes guests book very inexpensive places but expect a Ritz-Carlton experience. I'm not saying that's the case here, but just offering a perspective from the host’s point of view.
That said, if this isn’t a budget stay, then the host should absolutely provide hot water in both the kitchen and bathroom taps. From your description, it doesn’t sound like a fault. It sounds intentional.
I recommend contacting Airbnb customer service right away. They are usually very responsive in situations like this. Let them know that the place isn't livable for you and ask them to help find an alternative accommodation, even a hotel if needed.
According to Airbnb's amenities list, there is no such thing as partial hot water. Hot water means hot water. They may also suggest a partial refund, which could be a reasonable option.
In short, reach out to Airbnb now.