---
title: Why is my AC fan coming on WITH my furnace all of a sudden?
description: Check your settings on your thermostat to make sure the AC fan is set to auto not ON when not using the AC unit.
url: "https://teci-rv.com/docs/why-is-my-ac-fan-coming-on-with-my-furnace-all-of-a-sudden/"
updated: "2024-11-30"
category: Appliances
tags:
  - furnace
---

# Why is my AC fan coming on WITH my furnace all of a sudden?

Check your settings on your thermostat to make sure the AC fan is set to auto not ON when not using the AC unit.