A faulty or dirty ignition or sensor is a relatively easy fix so follow these steps and you may be able to solve the problem yourself.
Electronic ignition furnace won t light.
When your furnace fails to ignite the first place to look is the pilot light.
Because an electric ignition does not need constant power the way a pilot light does it contributes to energy savings.
If your furnace is an electronic model with an automatic ignition for the pilot light but it won t light there may be an issue with the ignition.
The pilot light or ignition sensor is usually the most common issue when your furnace will not ignite.
When the thermostat calls for heat 24 volts are sent to the electronic ignition control module which energizes the furnace blower and other systems and sends 120 volts to the hsi.
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To determine this turn off the thermostat.
But now an electric ignition system have started to replace pilot lights.
This system uses a pilot flame but the flame lights only when there s a call for heat from the thermostat.
The hsi heats up to around 1 800 f to 2 500 f and glows red hot.
This is typically the problem if you can hear your furnace click on but it does not fire up.
If you have a newer furnace or one with an afue rating above 80 it most likely has an electronic ignition system.
The furnace s control board might not be supplying the voltage to the ignitor.
Unlike older pilot lights which have to be lighted by hand automatic pilot lights now commonly found in most home furnaces are regulated by a thermostat and only ignite when needed.
If your furnace lights and the gas stays on for 8 to 10 seconds then shuts right back off then you can try to clean your flame sensor with light sand paper emery cloth or steel wool.
The standing pilot light was the regular way to ignite gas powered furnaces for almost as long as these heating systems have existed.
A furnace equipped with an electronic igniter cannot be lit manually.
Never attempt to light a furnace by a flame manually especially if the furnace has an electronic igniter.
The most common reason for this problem is because the pilot light is not on.