These days, the first question from technical help is always, "Well, did you try turning it off, then back on?" Even when it comes to natural gas furnaces, resetting the system can help sort out any issues you might be suffering. Most modern furnaces have circuitry that can go awry, and tripping the power supply can get things back to normal.
This has been known to solve some problems, such as the furnace blowing cold air or just not giving enough heat. So, before calling a technician, always follow tech rule number one: Turn it off, then back on.
Resetting Your Furnace
Today, natural gas furnaces usually come with automatic ignition options, making this task simpler for some folks. If you've got an older model with a pilot light – that ever-burning blue flame – resetting the furnace can intimidating, but it's an easy process.
The good news is, once your natural gas furnace resets, things should heat up within the hour.
Being Power Smart
If you've had troubles with heat, and you're restarting the system to get around that, make sure that your breaker panel hasn't shut off. That would cause the system to go offline. In case you've never learned circuit breaker safety basics: Never check a circuit breaker without completely dry hands, and only touch it with one hand at a time.
If the breaker panel control is engaged (flipped up) as it should be, then go to your furnace and power it down. Simply locate the furnace's power switch and turn it to "off."
Now, return to the breaker panel and turn the furnace breaker to "off," which is flicked down.
On the furnace, remove the access panel. This is a door or a metal panel that covers the controls and inner-workings of the furnace. Some panels just open, but others will need to be lifted, then removed.
Inside, there should be a gas control valve. Turn this off.
Clear the Air
The gas needs to dissipate before you reset the furnace. Let the air clear for at least five minutes. This is the perfect time to go make yourself a nice cup of coffee.
Flipping the Switch
Now, what you do after turning the gas back on will depend on your furnace type. (Don't turn your gas back on just yet.) If you have an ignition furnace, then skip the step after this and move straight to "Flip the Breaker."
If you've got an old-school pilot light furnace needing to be lit, then you'll need a long barbecue-style lighter so you can ignite the pilot light manually. Continue to the next step after this one.
Either way, act quickly once the gas is back on, so gas doesn't build up for more than a few seconds. If something interrupts you and a delay occurs, do not proceed with ignition – instead, turn the gas off for a few minutes so it dissipates, then try again.
Ready? Okay. Turn the gas valve back on.
Lighting the Pilot Light
As mentioned, automatic-ignition furnace owners can skip to the next step.
Turn the switch to "pilot." Light your barbecue-style long lighter and reignite the pilot light. Give it a minute. Does it stay lit? Great! If not, try lighting it one more time. If, however, the pilot light doesn't stay lit, you may have a problem with the gas line, a clogged air filter, the gas-to-air ratio or a few other matters – all of which need either a different "how to" article or a call to a service tech.
Flip the Breaker
Before you can turn the furnace back on, you'll need to return to the breaker panel and re-engage the furnace breaker by flipping it up.
Turning the Furnace on
For those with automatic ignitions: Turn the furnace on. This kick-starts the igniter.
Automatic ignitions can fail, as they usually need replacing every few years. So, if this step doesn't restart the furnace, then you may require a new ignition source for your furnace.
If, however, you've got a standing pilot light version of furnace and the pilot light has been lit already, then turning on the furnace should start generating heat shortly.
Finally, replace or close your panel cover.
If That Didn’t Help…
If resetting your furnace didn't solve your problem, many other factors can impede function, from clogged air filters that make the intake fan shut down to poor gas/air ratios. Other troubleshooting and maintenance steps may solve your problems before you must resort to the expensive solution of calling in the pros.
But, if you're lucky, this did the trick and your life's looking warm and cozy in an hour or so. In the meantime, make some cocoa and bundle up.