Several factors can stop a furnace from igniting: Thermostat Malfunctions: Incorrect thermostat settings or a faulty thermostat. Fuel Supply Problems: Insufficient propane supply, closed valves, or leaks. Ignition System Failure: Issues with the pilot light, electronic igniter, or other ignition components.
Defective Igniter or Pilot Light
If it clicks but your furnace won't ignite after the combustion cycle, the electronic ignition systems probably need to be replaced. In cases where the furnace ignition starts normally but only stays on for a few minutes and then goes out, a new pilot light likely needs to be installed.
If your furnace won't kick on when you turn the thermostat up, it could be due to a variety of reasons such as a tripped circuit breaker, a faulty thermostat, or a problem with the furnace itself like a malfunctioning igniter or gas valve. Checking these components might help you figure out the issue.
You can reset the ignition on your furnace simply. To do this you must cut the power to the furnace first by turning off the circuit that powers it. Once the power is off you can remove the burner door to reveal the ignitor. Turn this to “off” and leave it off for at least 5 minutes.
turn off the power, take a dish cloth or scrubby pad and clean the thermocouple, itll be located where the pilot flame is. then return power and see if it fires up.
Several factors can stop a furnace from igniting: Thermostat Malfunctions: Incorrect thermostat settings or a faulty thermostat. Fuel Supply Problems: Insufficient propane supply, closed valves, or leaks. Ignition System Failure: Issues with the pilot light, electronic igniter, or other ignition components.
Checking your thermostat is the best place to start. Make sure it's set to “heat” and that you've set the temperature higher than the current room temperature. If that doesn't resolve the problem, try switching your fan to “on” to force the furnace to start working.
Most likely, your furnace is making a clicking noise and not providing heat because your furnace's spark igniter is trying to ignite your pilot light or burners but is failing to do so. In other words, there's an ignition system malfunction that needs to be fixed. Otherwise, your furnace won't start.
Typically, you'll find it inside the air handler, either next to or above your furnace. In most newer systems, the button is often directly next to the blower motor, while in older systems, it may be harder to spot as it is sometimes underneath or behind the motor.
If no gas is flowing to the pilot light, you obviously won't be able to get it to light. This can happen because the furnace's main gas valve isn't fully open or if your gas supply is shut off or interrupted. There is also a chance that the pilot tube that supplies gas to the flame is clogged.
If your heater doesn't start, chances are the problem stems from having a dirty furnace. Having dirt on your blower motor or flamer sensor could render your furnace unable to perform. When the blower motor is too dirty, it won't pass enough cool air to the heat exchanger, leading to equipment failure.
Furnace is not producing heat.
Possible causes include a broken thermostat; the thermostat being set too low; an out pilot light; a blown fuse or circuit breaker; a closed gas valve; or electronic ignition problems.
There are several reasons why your furnace may not turn on. The most common include a broken thermostat, gas line issues, clogged air filters, blocked ductwork, a tripped circuit breaker, and issues with the furnace itself.
Furnace Not Igniting Because of Incorrect Thermostat Setting
Make sure the thermostat is set to heating and that the temperature is set high enough to actually turn the furnace on. It may be set at too low of a temperature to activate the furnace.
The Short Answer Is: Warning signs of a bad furnace ignitor include the furnace not starting or heating, a noticeable clicking sound without ignition, or frequent short cycling where the furnace turns on and off rapidly. Additionally, if the ignitor appears cracked or discolored, it may need replacement.
If your furnace won't come on, check the ignition sensor. A dirty sensor could be the reason why your furnace won't stay on or even why your furnace won't stop blowing cold air. Only if the furnace's heat exchanger — the part that actually heats the air — senses an ignition, will it power on the furnace.
If the thermostat clicks but the AC or furnace doesn't turn on, most often it's because the filter is clogged. A blocked filter will restrict airflow. The particles it's designed to trap eventually clog the filter media, and the system will be unable to generate heat or cool air.
Check the pilot ignition light.
(Electronic ignitions will not have a pilot light.) If your furnace clicks on or initiates the start cycle, but does not fire up, you likely have a faulty or dirty ignitor/sensor. This is one of the most common furnace problems.
Most modern gas furnaces can be reset by turning off the power, waiting around 20 seconds, then switching the power back on. Other furnace models may exit lockout after 1-2 hours and attempt to power on again.
If nothing's happening when you're expecting the whir of a blower, check the circuit breaker and fuse. At your electrical panel, make sure all switches related to the HVAC system are on. Reset any tripped breakers and replace all blown fuses, and your furnace should kick back on.
The first thing to check is your thermostat. It might be clicking yet failing to trigger the heating. Ensure it's set to 'heat' mode and the temperature is above the current room temperature. Incorrect settings or a malfunctioning thermostat can be a primary reason for the furnace clicking but not turning on.
Check the Power Source Sometimes the problem between the thermostat and your furnace is as simple as replacing the batteries. Many digital thermostats use standard batteries to power their functions. Also make sure to check there is power at the furnace as well.
The first motor to come on will be the inducer motor.
Not a large motor by any means, but it's the one that gets rid of the fumes spent by the flame that warms your home. The control board and a pressure switch acknowledge that the inducer has come on and is working properly.