Can a Bad Thermostat Cause a Furnace Not to Work?
When you turn your heat up on your thermostat but the furnace doesn’t switch on, you might wonder: Can a bad thermostat cause a furnace not to work?
The short answer is, “Yes,” but before you search, “fix heater near me,” read on to understand why. The more you know about furnaces and boilers, the easier it becomes to detect issues before they become full-blown problems.
At Cool By Design Air Conditioning Experts, we can address your thermostat problem with repairs or by replacing the thermostat.
How a Malfunctioning Thermostat Affects Furnace Performance
In general, the impact of a faulty thermostat on furnace operation is that it leads to inefficiency. At best, your furnace runs at the wrong temperature.
If the thermostat reads your home as warmer than it is, it won’t start up the heat. If it reads the home as colder, your furnace will run hotter than it should. The furnace can also cycle on and off quickly, which wears out the system’s motor.
A malfunctioning thermostat means that your system may use more electricity. It also won’t last as long because it runs more often than it should.
Can a defective thermostat disable the furnace? Yes, it can cause the unit to switch off if it reads the temperature as too high.
Common Thermostat Issues and Furnace Dysfunction
Diagnosing furnace problems related to the thermostat can be tricky. It takes specialized equipment and knowledge, which means it’s a job for the experts.
If you’re asking, “Can a bad thermostat cause a furnace not to work?” here’s what the technician looks for.
Miscalibration
This is the most common link between a bad thermostat and furnace failure. If the furnace can’t read the temperature properly, it may be a degree or two off or several degrees off.
You’ll notice that the furnace doesn’t turn on until it’s extremely cold or that the air becomes over-hot and stuffy. This is because the thermostat isn’t turning on or off at the right times.
Wrong Location
Your thermostat may be functioning completely correctly but be in the wrong area. If the sun shines directly on it, it reads the temperature as too high. If the thermostat is in the path of a draft, it reads the temperature as colder than it is.
Placing the thermostat too close to electronics that emit heat can also cause incorrect readings.
Short Cycling
There are many reasons that a furnace might short-cycle, but a faulty thermostat is the most common. A short-cycling furnace switches off earlier than it should, only to switch back on a little later.
This cycling not only wastes electricity but also stresses your furnace motor. The best-case scenario is that your unit doesn’t last as long. The worst is that the motor burns out.
Broken Connections
What happens if the heat doesn’t turn on at all or you can’t turn it off? The most common cause is a loose wire between the furnace and the thermostat. This could be due to rodent damage, normal wear and tear, or even a burned circuit.
If you can’t get the furnace to switch on, it probably means that the thermostat isn’t connecting to the motor. When you can’t switch the fan off, it’s likely for the same reason.
Should You Repair or Replace Your Thermostat?
Our team aims to fix your thermostat rather than replace it. However, we might recommend replacements when your current unit:
- Is very old
- Requires expensive components
- Will need ongoing repairs
- Is outdated or no longer suitable for the task
Our technicians will always suggest the most cost-effective option for you. We might also recommend upgrades if they feel you’ll truly benefit from the more modern features. For example, we might recommend installing a smart thermometer to help you save electricity going forward.
When we suggest replacing your current unit, we’ll walk you through your options to find the best fit for your budget and lifestyle.
Contact Cool By Design Air Conditioning Experts for Help With Thermostat Issues
Cool By Design is your go-to heating and cooling team in Florida. Now that you know that the answer to “Can a bad thermostat cause a furnace not to work?” is “Yes,” what else can we help you with?
Are you curious about locating the evaporator coil in the furnace, or do you need us to repair your unit for you?
Call Cool By Design Air Conditioning Experts at 954-417-1580 for HVAC service you can rely on.
