How do I stop being the help desk for my neighbour's short-stay guests?

A visitor knocked while I was eating dinner and asked how to make the heating work in the flat next door.

I said I didn't know. She showed me a message from the host: “If you get stuck, the neighbour at number 4 is helpful.”

That host is my neighbour. Two months ago I explained the recycling bins to one guest who had knocked at the wrong door. Since then, guests have asked me where the spare towels are, whether they can leave bags after checkout and how to connect to the flat's Wi-Fi. I cannot answer most of those questions.

I sent my neighbour a photo of the message. He replied, “I meant local tips, not property management,” then asked if I could just show this guest the heating switch. I had never been inside his flat and wasn't going to guess.

The guests are arriving with a reasonable expectation somebody gave them. I don't want to take my irritation out on a visitor standing in the corridor. I do want my flat number removed from the instructions.

How should I handle the guests who still have the old message? Being polite at the door has started to feel like agreeing to another person's booking.