Many new furnace owners panic when they first notice that there is no longer a little flame contently burning inside their unit. They immediately assume that something is wrong, because if this were the old unit they would be right. Nowadays, furnaces usually come with an electronic ignition rather than a standing pilot. Though you could still purchase a unit with a constant flame, learning a little bit about electronic ignitions may convince you to convert to this new technology.
Standing pilots have been used for years as the initial source of flame when igniting a gas furnace. They consist of a pilot assembly and a thermocouple. The pilot assembly holds the flame and is attached to a gas source. The thermocouple is placed near the flame, and when the furnace calls for heat it begins to heat up. If the pilot is working properly, the thermocouple will send an electric signal to the gas valve to open. The gas valve will release gas into the unit, and the combustion process will begin.
If the pilot is not working properly, the thermocouple sends a different signal. If the pilot fails to light or if there isn’t enough heat produced, the thermocouple will shut down the gas valve. This is a precautionary measure that is taken so that gas doesn’t spill into the unit. If enough gas were allowed to pour into the unit, even the slightest spark could cause an explosion.
The problem with standing pilots is that they need a constant flame burning. That flame needs gas to stay lit. It is this feature of the pilot that makes your furnace less energy efficient. The gas used to keep that flame alive is being wasted in between cycles when heat is not being generated for the home. That translates into higher energy bills because your furnace is using gas inefficiently.
Electronic ignitions were the answer to the problem with standing pilots. This type of pilot doesn’t use a constant flame no matter which style your furnace uses. The different styles of electronic ignitions include:
- Direct spark ignition
- Intermittent pilot ignition
- Hot surface ignition
Direct Spark Ignition
An electronic ignition that is uses direct spark ignition never uses a pilot light. The system consists of a flame sensor and an ignition control module. The ignition control module will light the main burners when the thermostat calls for heat. The flame sensor is there to sense the flame created by the burners. If the burners do not fire up, the flame sensor will shut down the gas valve. The flame sensor performs the same precautionary job as the thermocouple does in a standing pilot.
Intermittent Pilot Ignition
This type of electronic ignition does use a pilot, but it is only lit when the thermostat calls for heat. It uses a pilot assembly and a flame sensor. A spark at the tip of the pilot assembly will light the pilot, and then the pilot heats the flame sensor. Once the flame has been sensed, the flame sensor tells the control board or the ignition control to send an electric signal to the gas valve to open. Though this type of pilot uses an actually flame, it is still much more energy efficient than the standing pilot because it doesn’t waist gas in between cycles to keep the light lit.
Hot Surface Ignition
A hot surface ignition uses a heating element. This element will heat up and glow red when electricity is sent to it by either the circuit board or an ignition module. Once it is red hot, the gas valve will open, and as the gas passes over the heating element it will ignite and fire the burners. If the burners fire normally, the flame sensor will sense the heat and let the burners stay lit and remove the electricity flow from the heating element. If it doesn’t fire properly, the flame sensor will shut everything down.
No matter which type your new furnace has, make sure that is an electronic ignition. Every single one of the furnaces offered by Four Seasons Heating and Air Conditioning use an electronic ignition. The more energy efficient our units are, the more money that we can save our customers on their monthly energy bills. Four Seasons knows that installing a furnace is a big investment, and the only way to really make it worth your while is by selling only reliable and energy efficient furnace units.