My Heater Won’t Turn On! [Where To Check And What To Do]

When the cold weather comes, it should only take a few seconds from the moment you turn your thermostat to “Heat” to that first rush of comfortable, warm air rushing through your vents. 

But what if that warm air never comes? 

The clock is ticking once you try to turn on your heater but nothing happens. By then, it’s cold outside and getting chilly inside, too.

You can call for heater service — and that’s probably a good idea — but unless you pay a lot extra for priority service, it’ll be at least a day before anyone can come out. 

But, you don’t have to wait even that long to start troubleshooting. 

And, with any luck, you can cancel that call after solving the problem yourself. 

In this article, we’ll walk you through some common problems that will prevent your furnace from firing up. It’s important to know the common HVAC warning signs and how to recognize what various noises coming from your furnace could mean.

Then, we’ll tell you how to avoid these problems in the first place. 

Read More: How To Avoid The Cracked Heat Exchanger Scam

Meanwhile, if you need heater service in the Metro Boise Area or up in Valley County, call or email us here at Snowflake Air! You’d be surprised how often a small, inexpensive problem will stop your heater from turning on. 

When that’s the case, we can get you up and running again quickly and for much less money than you’d think.

Three Common Reasons My Furnace Won’t Turn On 

   1. The Filter Is Clogged

   2. Thermostat Is Set Incorrectly

   3. Problem With The Furnace 

The Filter Is Clogged

When was the last time you changed your air filter? If you can’t remember, that may be the problem. 

Your filter — that white cloth stretched across a frame — sits between the ductwork and furnace. Its job is catching dust and dirt before it gets into your heater. But, eventually, it gets so full of junk that it won’t let air pass through, either. 

When that happens, the system recognizes that there’s no air coming in. So, it won’t turn on until you correct the problem. 

What To Do

Put in a new air filter every month when your heat or AC is running. And, change it every three months when it’s not on. This way, it never gets so clogged that air can’t pass through it. 

And, if your filter screen is grey or darker when you remove it, then you’ve probably found the problem. If it’s got that much buildup, it’s clogged. 

Filters are inexpensive, and changing them out is easy. You can also click below to join our air filter program, and we’ll deliver them straight to your door all year long!

Thermostat Is Set Incorrectly

Setting a thermostat is pretty easy. Even today’s more sophisticated models and smart thermostats, the process is straightforward. 

But, it’s just as simple to make a mistake or forget to adjust something after not using it for a while. That’s common in the late fall, well after you stop using the AC. Or in the spring after the heating season. Either way, you can end up with a system that won’t turn on. 

What To Do

First, make sure the batteries have plenty of power. Sometimes low battery power causes the thermostat to malfunction.

Next, make sure you set the thermostat to “Heat.” Otherwise, a system on “Cooling” waits for the temperature to go over your call setting to turn on the AC. You want it to turn on the heat once it dips below the call. 

Also, make sure your fan is set to “Auto” and not “Fan Only.” With “Fan Only,” the system will turn on, but you’ll only get cool air. 

That’s because the fan blows, but your furnace won’t produce heat. It’s beneficial for circulation, not for heating or cooling. 

Last, try resetting the thermostat completely. There may be some timer or setting that’s preventing the system from turning on. It’s even more likely with more sophisticated models that offer more options. 

Problem With The Furnace 

Yes, we know just saying “furnace problems” is vague and not all that helpful. But, once you get into electrical or mechanical issues, there’s not much you can do without a serious background in HVAC repairs. 

And, we wouldn’t suggest that you take off the panel and start tinkering around. But, if you do feel comfortable taking a look under the hood, you can do a few quick diagnostic checks yourself. 

Again, the odds are you won’t be able to fix anything at this point. But, you may have a little more peace of mind while waiting for a tech. 

Or, you may just get lucky. 

What To Do

First, check for a blinking light. Just like with most water heaters, a blinking LED light can indicate a problem and what’s going wrong. 

You can match the blinking pattern with a sticker on the panel that tells you what it means. Or, check the manual if there’s no sticker. 

You may also see an on/off switch or reset button for a pilot light. If there’s an error message saying the pilot light is out, follow the instruction to use the ignition switch. 

And, of course, make sure the on/off switch is in the “On” position.

Benefits Of A Heater Tune-Up In The Fall

As stressful as it can be not to have heat when you need it, a lot of times, the fix is fast and easy for a trained professional. Sometimes it’s something as simple as a loose wire or a blockage preventing airflow. 

One very easy way to head these issues off is by getting a heater tune-up in the fall before you start using your system. 

When you get a tune-up before winter, a trained technician checks dozens of inspection points throughout your system. They’ll catch all those minor problems you wouldn’t find on your own and fix them before they cause a problem. 

A tune-up only takes about an hour, and you can get one even if you’ve started using your system for the season. Need more reasons? How about lower energy bills and better comfort? 

Yes, a tune-up can do all that, too.

Heater Repair And Tune-Ups In The Metro Boise Area

Snowflake Air is the trusted name for heater repairs and tune-ups in Kuna, ID Caldwell, Garden City, and across the Metro Boise area. We also service McCall, Donnelley, and Cascade up in Valley County. Check out our hundreds of five-star reviews, and when you’re ready, call us at (208) 205-9078 for an appointment.