Why Won’t My Furnace Start Up?


This is a situation nobody wants to encounter on a cold winter day or night: turning on the furnace only to have the furnace do nothing. Maybe the blower fans come on, but there’s no warm air coming from the vents. Or maybe even the fans won’t come on.

If your first instinct is to call an HVAC professional to repair the furnace, you’re thinking on the right track. You should never attempt to open up the furnace cabinet to repair the furnace yourself, nor have a non-professional do it.

However, before you call professionals for repairs, we’d like to go over some of the causes of a failed furnace. A few of them are basic troubles you can quickly correct. Once you’ve exhausted those options, it’s time to have the experts in.

Some Simple Causes of a Failed Furnace

1. Power failure

If it’s daytime when your furnace won’t come on, you may have a power outage in the house and didn’t realize it yet. Check lights and other appliances to see if this is the case.

2. Tripped circuit breaker

The blower fan for the furnace can potentially overload a circuit in the electrical panel, causing a breaker to trip and cut off voltage. Check the electrical panel and reset any tripped breakers. However, if the breaker problem persists, then there’s probably an electrical fault in the furnace that needs professional repairs.

Read More: 5 Reasons Your Circuit Breaker Trips

3. Mis-set thermostat

Sometimes it really is this simple! Check the thermostat’s programming to make sure that the furnace does know it’s supposed to come on. Confusion with programmable thermostats may sometimes lead to a furnace that isn’t turning on when it should.

Read More: No Heat? Self Diagnose Thermostat First

4. Clogged filter

When only lukewarm air comes from the vents, check on the furnace filter. It may be extremely clogged up and blocking airflow, which results in a drop in the amount of air getting heated. Change the filter for a clean one, and keep up with routine filter changes every 1 to 3 months.

Read More: Which Way Do You Put A Furnace Filter In?

More Complex Causes of a Failed Furnace

When none of the above is the reason your furnace isn’t doing the job, leave the diagnosis to the professionals at Service Legends. There are many potential reasons for a furnace that won’t heat or turn on:

  • Burnt-out blower motor
  • Failed electronic ignition system
  • No gas flow
  • Electrical failure (yes, this applies to gas furnaces as well as electric ones)

You can trust licensed HVAC technicians to accurately identify the problem so it can be fixed. They will also ensure the repair work is done safely, which is extremely important for natural gas furnaces.

We’re Ready to Rescue Your Furnace!

We know that when you need Des Moines, IA furnace services, you probably need them as soon as possible. You can count on fast repair work whenever you call us. We can fix whatever trouble has stopped your furnace, or we can arrange to have it replaced. (There are times when a replacement is the best option.)

515-657-6634Request Appointment Online

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