Your heater is on and you and your loved ones are ready to enjoy a warm and cozy home. And yet, your home feels cold because your heater is not blowing any air out!

It’s time to figure out why your furnace is not blowing air out, and find a solution.

As with many heating problems, there are many reasons for your heater to stop blowing air, some of which you can troubleshoot yourself and some of which will require a licensed HVAC contractor. Place your trust in the award-winning services of UGI Heating, Cooling & Plumbing.

Here are some possible causes and troubleshooting steps you can take to get your furnace blowing air again:

Check Your Thermostat

While it may seem like a no-brainer, make sure that your thermostat is set to a certain temperature and no one is turning it off, or down – so check with your significant other or housemates that the temperature is set correctly! If it’s not, set it for five degrees higher than the temperature in your house and see if the heater’s fan comes on.

A common misconception is that, if your thermostat is set to 70, the heater will kick on when the temperature drops to 69 degrees. In actuality, most systems have a buffer of about 3 degrees, so, in this instance, the heater would not kick on until the temperature lowered to about 67 degrees.

After checking the temperature setting, ensure that it’s in ‘heat mode’ instead of A/C mode – this also seems simple, but programmable thermostats get more and more complex meaning that there are more ways to mess them up!

Next, check that the date and time on your programmable thermostat are correct. The point of a programmable thermostat is to save energy, and it does this in the winter by lowering the temperature of your home when it thinks you are at work or in bed. However, if the time is off, your heater might think it is 2pm on a Monday when it’s actually 10am on a Sunday, causing your furnace to stop blowing air and you to freeze over your morning coffee.

Another thing to consider is replacing the batteries. The most likely cause of an improperly programmed thermostat is a power outage with a dead battery. This would cause the whole system to reset itself, and, it’s possible for your thermostat to dump its settings even if the battery is not dead but low.

For more tips on understanding and troubleshooting your thermostat, check out our post Everything You Need to Know About Thermostats.

Check Furnace Circuit Breakers

If you’ve had electrical work done lately, or had a new water heater installed, it’s possible that your furnace circuit breaker was turned off, so it’s a good idea to go to your main power distribution panel and check the circuit breaker.

Also, it’s not uncommon for your blower motor (the fan) to have a separate circuit breaker, so make sure you check that as well.

Next, check the furnace itself and the surrounding walls for another on/off switch or circuit breaker and if any of these are off, turn them on once (only once, for safety) and allow your system to run. If they trip off again, this is a sign that there is a problem with the wiring of your system, so do not keep resetting faulty circuit breakers as this is dangerous and could start an electrical fire. If this is occurring in your home, it’s time to give us a call.

Check Your Furnace Air Filter

Next, check your heater’s air filter, as this can cause a furnace to stop blowing air.

Your filter could be so saturated with dust and debris. In that case, even though the furnace is actually blowing air, your clogged filter is blocking it from making it into your ducts. You should be changing your air filter every three months or so.

Every modern furnace is equipped with a safety shutoff that will be tripped if your furnace gets too hot, and a clogged air filter can cause your furnace to overheat, shut itself off and give you the illusion of a furnace not blowing air.

Check Your Furnace Blower Fan

After ruling out all of the possible problems above, the most likely cause of a furnace not blowing air is a problem with the blower fan, or with the furnace fan limit control switch, which would require a more advanced troubleshooting, best left for an experienced HVAC technician.

We hope this guide helps you troubleshoot your furnace. However, if it’s still misbehaving, it’s best to give us a call and have an expert take a look.

Rely on UGI Heating, Cooling & Plumbing – our skilled HVAC contractors are here to ensure that your heating system is operating at its best; and if you need a new one – we’ll make sure you’re getting the right system based on your budget, environment, and home needs.

Keep Comfortable All Winter Long – for furnace repair, furnace replacement, and other heating solutions make an appointment today with the leading HVAC company serving the Lehigh Valley PA, Harrisburg PA, Lancaster PA, Reading PA, and all the surrounding towns.

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