Why Does My Heater Come on When System Is Set to Cool?
Noticed a sudden spike in your electricity bill? Or maybe your air conditioning runs for extended periods of time without cooling the house?
If so, you might be experiencing a malfunctioning HVAC system. More specifically, your system’s heater is turning on even though the air conditioner is set to “cool.”
What is causing your heater to activate? Electrical issues within your central AC unit are the most likely causes of your heater turning on when it shouldn’t. Shorted wiring, faulty electronics in your furnace, or an electrical problem with your thermostat, for instance, could all explain the issue.
Bottom line, when you suspect your heater is turning on improperly, contact an HVAC specialist. Working with live wires and electrical components can be very dangerous. But the good news: This issue can typically be reversed with a quick repair.
3 Air Conditioner Issues that Can Cause Your Heater to Turn On
One of the quickest fixes for this problem: Check to see if your thermostat is set to “cool.” It sounds overly simple, but you’d be surprised how easy it is to change settings accidentally.
If your air conditioner is, in fact, set to chill, a range of issues could be triggering the heater to turn on. The most common include:
- A Faulty Thermostat
Most solutions for this problem require the expertise of an HVAC technician. But you can examine your system’s thermostat. If the thermostat has lost power, this could be the source of your problem, for example.
If your thermostat is battery powered, try changing the battery. Also, if you see a blank screen, check to see if a breaker has tripped. Worst case scenario, the thermostat is defective, in which case, you’d need to have the thermostat replaced.
- Thermostat Connection Is Faulty
The thermostat’s connection to the furnace and AC unit may become disconnected. Or the wiring from the thermostat to the units could short out.
In other words, your thermostat may be in “cool” mode, but their furnace and AC unit have no way of knowing that. This can trigger the heater to turn on. These shorts can be caused for some reasons. For example, water damage and even rodents can both cause a short. Ultimately, a heating and cooling expert can help you restore the connection.
- Electrical Problems at the Furnace
Your AC and heater work in close cooperation together. In fact, even during summer, the blower within your furnace is responsible for circulating cold air throughout the home.
Inside the furnace though, there’s a complex network of wires and circuit boards. Over time, or due to water damage, these boards can malfunction and short out. And that’s a common cause of the heater issue.
In a nutshell, the furnace’s motherboard tells it exactly what to do. When it’s not properly working, the “cooling signals” the furnace receives from the AC unit and thermostat can’t be properly understood – which can trigger the heater on.
Contacting a Heating and Cooling Company to Restore Your AC System
There’s nothing quite as frustrating as a malfunctioning HVAC system. But the good news is that most HVAC problems tend to have relatively quick and low-cost solutions.
In the case of a heater that’s turning on, the simplest fix might be changing batteries in your thermostat or resetting a tripped breaker. Even more complex solutions like a circuit board replacement or wiring restoration can be finished quickly and easily.
Bottom line, if you’re experiencing this problem, contact a heating and cooling specialist. A technician will be able to diagnose the cause quickly, and get your AC system up and running in no time.