Troubleshoot your non-working heater by checking the thermostat's settings and power status, replacing clogged air filters, and inspecting your circuit breaker and furnace power switch. Taking 15 minutes to inspect these basic elements often resolves heating failures without needing professional help.
To get your heater working again, try these steps:
How Long Can My House Stay Warm Without Heat? Most homes begin losing heat within a few hours, and depending on outside temperatures, can drop to unsafe levels within 12 to 24 hours.
To reset your heater, locate the system's power switch (usually a light switch near the furnace or inside the front panel). Turn it off, wait 3 to 5 minutes, and turn it back on. Alternatively, flip the dedicated heater/HVAC breaker at your home's main electrical panel off, wait a full two minutes, and turn it back on.
Let's dive into each of these a bit more.
To determine if your furnace fuse is blown, turn off the power to the unit, remove the automotive-style fuse from the control board, and inspect it for a broken metal filament or dark burn marks. Alternatively, use a multimeter to check for electrical continuity.
Resetting can recalibrate the temperature sensor. Failure to Turn On HVAC System: A thermostat reset reboots its system and attempts to restart normal functioning. This resolves problems where it fails to turn on your AC, heat, or fan.
The reset button's location depends on your thermostat type. For older models, it is usually a recessed button on the circuit board (often behind the faceplate) or a dedicated button on the front or side. For modern smart thermostats, you typically reset the device through the digital menu.
The Most Common Home Heating Problems
While chances of freezing to death in your home are small, there's a greater danger of death by fire, lack of oxygen or carbon monoxide poisoning.
5 Warning Signs It's Time for Furnace Replacement
The heat exchanger is often considered the most costly part of a furnace to repair or replace. It is a critical component that transfers heat from the combustion process to the air that circulates throughout your home. Over time, heat exchangers can crack due to the constant heating and cooling cycles they undergo.
To get your furnace to kick on, first verify your thermostat is set to "Heat" and raised at least 5 degrees above room temperature. Next, check that the furnace power switch (usually resembling a standard light switch on or near the unit) is toggled "ON".
A frozen pipes furnace failure can cause major problems inside your home. Ice builds up fast in unheated spaces, and when frozen water expands, it can burst pipes wide open. That kind of mess is the last thing anyone wants during a winter heating outage.
You may feel this is the easiest and most harmless step, but the reset method is not the same for all types of systems, and it is not right to reset your system frequently. If you face the same problem more than once or twice, do not reset your system every time. It will damage your furnace.
Pushing the reset button on a thermostat clears errors and restores communication with your HVAC unit. However, depending on the type of reset, it will usually erase all custom schedules, temperature settings, and Wi-Fi configurations.
Get your heating running again with a few quick checks. First, ensure the mode is explicitly set to “Heat” and the target temperature is at least 3 to 5 degrees above your current room temperature. Next, check if your unit uses batteries.
A stuck car thermostat typically fails in two ways: stuck closed (trapping heat) or stuck open (allowing constant coolant flow). The exact symptoms depend on the failure position, ranging from rapid overheating to poor fuel efficiency and lack of cabin heat.
How can you tell if a thermostat is bad?
Typically, a furnace should cycle 3 to 8 times per hour, running for about 10 to 15 minutes each time. If it's cycling more frequently (short cycling) or running for 20+ minutes straight regularly, something's not right.
If your thermostat is on but no heat is coming out, the quickest fixes are to replace the thermostat batteries, reset the furnace’s power switch, or check your home's circuit breaker.
Capacitors are used in nearly every heating system, from gas furnaces to electric furnaces to heat pumps. Even though other parts can fail, like the ignitor in a gas furnace or the compressor in a heat pump, the capacitor is by far the most common part to fail on a furnace because almost every system relies on one.
A blown fuse needs to be repaired as soon as possible. We do not advise trying to change your circuit breakers or fuses yourself, as this can be a dangerous job and may even lead to short circuiting. Instead, enlist the help of a licensed and qualified emergency electrician for any electrical home repairs.
To know if a fuse is blown, inspect the filament inside the fuse. If the wire is severed, melted, or if the inside of the fuse looks dark or cloudy, the fuse is blown. You can also test it without removing it using a multimeter or a test light.