Weber County
Brigham City
Salt Lake


A combustion furnace uses an ignition system to light the burners that produce the furnace's heat. Thus, your furnace will struggle to heat your home if its ignition system malfunctions. Furnaces use different types of ignition systems with different efficiencies. Below are some of these ignition systems and their potential problems.

Furnace Ignition Types
Furnaces use different types of ignition systems. Below are four major types of these systems.

1. Standing Pilot Light
The standing pilot light stays on as long as the furnace is running. The flame stays on to ignite the furnace burners whenever the temperature falls below the set temperature. The standing pilot lights waste energy because it burns even if the furnace doesn't need its flame. The standing pilot light is relatively old technology and only exists in old furnaces.

2. Intermittent Pilot Light
Furnace manufacturers developed the intermittent pilot light to counter the inefficiencies of the standing pilot light. In this case, the pilot light only comes on if the furnace burners need ignition. The pilot light stays off the rest of the time.

Whenever the thermostat calls for heat, an electronic igniter produces a spark that lights the pilot light. The pilot light's flame then lights the burners. Both the pilot light and the burners turn off once your house reaches the desired temperature.

3. Hot Surface
Hot surface ignition uses a flat ceramic material to light the furnace's burners instead of a pilot light. Like the intermittent pilot light, the hot surface igniter stays off as long as the furnace burners are off. When the furnace calls for heat, it sends an electric current to the ceramic material and heats it. The red-hot material then ignites the burners.

4. Direct Spark
The direct spark ignition system dispenses with the need for a pilot light. Rather, the ignition system directly lights up the burners when the furnace calls for heat. The ignition system has an electronic system that stays off when the burners are off and produces a spark when the thermostat calls for heat.

Potential Problems
Your furnace burners might not light up, which means there is no heat if the ignition system has malfunctioned. Below are some causes of ignition system problems.

Fuel Problems
For ignition systems that use gas, the pilot system will stay off if it does not get adequate gas. For example, an intermittent pilot light with electricity and no gas won't light up. That might be the case, for example, if something has interrupted the gas supply to your house or your furnace's gas valve has malfunctioned.

Electricity Issues
For systems that use electricity, lack of electrical supply will keep the ignition system off even if the thermostat calls for heat. Improper wiring, electrical cabling damage, an electrical blackout, and a tripped breaker can cause such problems.

The pilot light’s heat or flame has to reach the burners for them to ignite. That might not happen if debris has clogged the pilot light's tip. For example, soot or dirt can accumulate on the pilot light's tip and insulate it from the burners.

Control Issues
A furnace's ignition system only lights up if the thermostat calls for heat. The furnace has an integrated control board that coordinates all its functions, including coordinating the thermostat and burners operations. A control board malfunction means the ignition system might not work because it won't get the correct signals.

Regular maintenance of your furnace may prevent some of its ignition issues. Prompt repair of ignition problems will ensure you always get the heat you need from your furnace. Dick Kearsley Service Center can help you with both of these things. We can also install or replace your heating system. Contact us for quotes on all your heating needs.


520 S State, Clearfield, UT 84015

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