furnace troubleshooting tips from greater comfort

Furnace Not Working? Here Are Some Common Problems to Know About

No one wants to suddenly discover their furnace isn’t working as it should or isn’t working at all. So what are the first things you can do before or as you call us to come out to help?

Ensure the furnace is…on.

You may wonder how you missed it, but one of the first things you can do is be sure the furnace is…well, on.

For those that feel comfortable in doing so, head to breaker box and fuse box and start there. In many cases, your HVAC may be labeled so you can be sure it’s set to on. Of course to reset the breaker, you’ll flip the switch to off before returning it to its on position.

In most cases with a fuse box, you’d look for signs like a melted fuse which you would want to replace. After replacing it, if you feel comfortable in doing so, then you can turn your furnace switch back to on and see if that does the trick.

Now let’s say you have ensured the power is back to on. As a part two to this, you also want to be sure the furnace is also set to heat.

Make sure the thermostat batteries don’t need to be replaced.

Is your thermostat wired to your electrical system, or is it battery-operated? If the thermostat is battery-operated, you’ll be happy you checked the batteries to see if that was your problem. It’s an easy fix, so it can be nice when that’s how simple the issue is! As a general rule of thumb, you may have to change out your batteries once per year, or even less often than that.

Make sure no debris are getting in the way with the thermostat.

Yes, the thermostat battery issues can be what’s to blame. But if there is some sort of debris that’s gotten in there, that can also stop it from working properly or working altogether (1).

Check that your filter is not dirty.

Another initial step to take a look at is the state of your filter. Your filters job is to help the furnace perform optimally and so if the filter is dirty or clogged, the airflow will be impacted, and you’ll think your furnace simply isn’t working. Not only that, it’s going to worsen your indoor air quality, which can sometimes even be felt, since part of what makes air “comfortable” is the overall indoor air quality.

If you haven’t already, set a calendar reminder as to when you should be checking your filters. Ask us about how often you should be changing out your filter. A lot goes into how often you’ll need to change your filter, so we want to be sure you’re changing it as often as it should. Also let us know if you have any questions about proper installation of the air filter, too, which will of course impact how well it works.

Make sure the furnace isn’t blocked by any objects. 

One last thing you can do is that you can make sure your furnace isn’t being obstructed by things like boxes or furniture. Whether it’s a toy or something that’s just been accidentally moved right by the furnace, large objects can end up blocking the return air grilles, which means the furnace will struggle to do its job (1).

A Great Reminder About Ongoing Preventative Maintenance

Troubleshooting can remind you why it’s so important to regularly change out your air filters, something we love to remind customers since it can help prevent so many common HVAC issues.

Changing your air filter—and doing so regularly—protects your heating and cooling system, and it allows it to last longer. If you’re filter is clean, your HVAC can work optimally; on the other hand, if it’s dirty, it restricts the airflow and it makes your HVAC actually have to work harder to get the same amount of work done.

Not only does it have to “work harder,” but imagine how your system is working inefficiently and ineffectively, so the actual comfort in your home is impacted, too, when you don’t change out the air filters on time.

Proper HVAC maintenance, including your tune-ups and changing out your air filters, is critical for comfort but for the longevity of your HVAC. For most home-owners, tune-ups will happen twice a year, and if we see anything that needs to be repaired or replaced, we’re able to share that with you during those tune-ups. (And, if you enroll in annual preventative maintenance plan, you not only save but you don’t have to worry about the maintenance getting done or not!)

To recap: By changing your air filters on-time and by doing adequate maintenance, you’ll be able to do your best to prevent issues happening to your furnace. So take the time for the preventative maintenance, and hopefully you can avoid having to do any of the troubleshooting tips described here.

What to Do Next When Your Furnace Isn’t Working 

If you’ve done these things (or at least those you feel safe doing) and you still believe your furnace isn’t working, give us a call. If you’re uncomfortable taking any of the steps described here, be sure to give us a call. Never take any steps that could be you or your family in harm’s way!

We take pride in being your go-to resource for dependable HVAC service and repair, support, and regular maintenance. We’re here to help you with all your commercial and residential heating and cooling needs.

You can also enroll in our Preventative Maintenance Program and you’ll save—plus you won’t have to worry that your regular, ongoing maintenance gets done.

To enroll in our preventative maintenance program or for service, contact us today at greatercomfort.com or call 859-491-4915.


  1. https://www.bryant.com/en/ca/current-owners/troubleshooting/

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