Is Your Furnace Blowing Cold Air, Not Coming On, or Cycling Frequently? We’ve Got Answers to Furnace Frustrations

furnace blowing cold airEven though the “winter” months are falling behind us, we in the Valley know that the weather here can be just as cruel in spring. And we expect to have our furnaces blowing well into March, if the rains and wind continue! But what if your furnace isn’t blowing? What if you’ve got a furnace blowing cold air, or nothing at all? You may be dealing with furnace frustration: Common problems that drive you batty and keep your house a little too cool for comfort! Our job is to make people in the Valley sane–at least when it comes to HVAC–so today we’ll talk about three frequent frustrations that folks face this time of year.

I’ve Got a Furnace Blowing Cold Air!

Furnaces heat air, fans push that air, and ducts deliver it throughout your house. Pretty simple right? But what if the air that comes from your vents is cool? Well, it takes a while to heat up…right? Sure, it can take a minute for your furnace to get the air nice and warm for you. But ten minutes? Twenty? Eventually, you have to admit–you’ve got a furnace blowing cold air around!

There are several reasons your furnace might be moving unheated air. It may seem silly, but first you need to make sure your thermostat is set to “heat.” Sometimes the problem is as simple as that! If the thermostat is set correctly (and isn’t broken), you can proceed to more in-depth measures. We’re not talking seriously invasive procedures, just a cursory examination of the air filters. Many HVAC systems are set up to turn off if they overheat, and any system that pushes air through a dirty filter is at risk of doing just that. If your system is working too hard to get the air through the filter, it may just turn off instead of frying the whole enchilada. This is a good thing, and if you suspect that’s what going on you’ll need an HVAC tech to get the system reset.[1. https://homeguides.sfgate.com/troubleshooting-furnace-thats-blowing-cool-air-64038.html]

Another possibility is that, if you’re using a gas furnace, your pilot light has gone out. While less likely, it could cause your furnace to stop heating the air that it blows through the ducts–after all, no pilot light means no heat. In theory, no pilot light should also mean no fan, but that’s not always the case. It’s possible that the fan will still move air even if that air isn’t being heated.

My Furnace Isn’t Blowing at All!

Just like the last issue, if your furnace isn’t blowing at all, the first thing to check is the thermostat. If that seems to be in order, the next area to look at is the circuit breaker. Like the thermostat, this may seem simple–but trust us, folks: the simple solutions are often the right ones! Even if the solution is a tripped breaker that can be reset, you should consult an HVAC contractor as well as an electrician. Breakers often trip for a reason: yours could be tripping due to a short-circuit, equipment failure, or a problem in the electrics that needs attention. If, like the thermostat, the breaker seems to be working, the next place to go is your air filter. A really dirty filter can seriously impede air flow. You may not be able to feel the air that’s being pushed through at all–or your furnace may be shutting off due to overheating (see the above section).[2. https://asm-air.com/heating/furnace-not-blowing-air-troubleshooting/]

Still stumped? Unfortunately, after that, we’re into the territory of thermocouples, fan motors, and limit control switches–and you’ll do best to call a professional! Any of those issues–or a host of others–could be the reason for your furnace not doing a darn thing when you turn it on. And all of those issues will be tricky to diagnose and fix unless you have a licensed HVAC contractor on your side.

My Furnace Works, But It’s Always Switching On and Off

How often is too often? Well, last week we had a client whose furnace was turning on and off every two minutes. This particular client was a light sleeper, used to the regular cycle of his system. So the increased “on-off” switching (coupled with inefficient heating) woke him up whenever it kicked on. In the HVAC world, we call this problem “frequent cycling,” and it has many possible causes. Air filters and thermostats (as always) can cause these problems, but so can foreign objects in the ducts or a furnace that’s simply too small for the space that needs to be heated.[3. https://www.startribune.com/a-diy-test-for-furnaces/230969331/]

In the case of our sleepless client, his furnace was receiving bad information from a thermostat older than the Reagan era. He upgraded to a new Honeywell model (programmable, no less!) and suddenly his older furnace had a new lease on life. Better performance, more manageable heating, and no more frequent cycle issues.

Like all of these issues, frequent cycling is common but not always easy to diagnose. It’s something that a good HVAC contractor can fix, though–and it’s worth fixing. No matter what you’re looking at, as winter moves into spring you should face furnace issues head-on: after all, they’ll be waiting (and worse) next fall!