3 AC Problems Causing Your Heater To Turn On

With spring in full swing, most homeowners have turned off their furnaces and are beginning to think about relying on their air conditioning systems on warmer days.

You expect that your AC unit will blow cold air when you turn it on, so it can be surprising to have your heater suddenly turn on again once you have switched over to your AC system. Your air conditioner and heater are closely linked, so malfunctions within the AC system could be causing your heater to engage.

1. Electrical Issues

Both your furnace and your air conditioner must be connected to an electrical source in order to work properly. This means that your HVAC appliances are susceptible to damage when electrical issues arise. A common indication of electrical problems is an HVAC system that begins to act erratically.

The blower motor on the furnace is responsible for moving cool air created by the AC unit in most homes. If the electronic motherboard inside your furnace becomes damaged, the signal triggering the blower motor can be confused. This will result in the heater running when it should not.

An experienced HVAC professional will be able to assess the condition of your furnace's electrical components to determine if electrical issues are causing your sporadic bouts of unwanted heat.

2. Faulty Thermostat Connection

Another AC problem that might be causing your heater to engage is a faulty thermostat connection. The thermostat allows you to control the performance of your HVAC system remotely. With the push of a button you can increase or decrease temperature, turn your HVAC appliances on or off, and control whether or not the fan blows air into your home.

Issues arise when the connection between the thermostat and the AC becomes faulty. You may set your thermostat to cool, but your AC won't turn on if the thermostat connection is bad. Instead, the furnace turns on.

Electrical shorts are most often the cause of faulty thermostat connections, and a professional HVAC service will be able to address these shorts to restore proper function to your HVAC system.

3. Broken Thermostat

A broken thermostat may be to blame for your heater randomly turning on. The thermostat measures the air temperature within your home and signals either the AC unit or the furnace to engage when the ambient temperature doesn't match the temperature you have set.

If the thermostat is broken, accurate temperature readings will be impossible. This could cause your heater to engage when it shouldn't. Replacing the thermostat should correct the problem and restore the reliability of your home's cooling system.