Five Common Furnace Heating Problems

There is only one thing worse than having a faulty furnace: not understanding what the problem is. Furnace and heating systems are extremely complex machines, which is why it is critical to hire a licensed & insured HVAC company for heating repair. Still, there are some common heating problems we see repeatedly.

So what’s the culprit that’s causing your heater to go on the fritz? If we had to bet on it, it’d be one of these five common heating problems:

1. Thermostat Problems

Your thermostat could be the troublemaker. Those wall stats are the brain of your heating system, telling the system when to turn on, when to turn off, and how long to run. Then you have smart thermostats, which can do even more thinking and learning. So when your furnace acts funny, the thermostat is one of the first places to look. 

There are a few indicators that point to an issue with the thermostat: 

  • Digital thermostat has no power
  • System is short-cycling, or constantly turning on and off
  • Heater turns on, but turns off before it warms the entire home
  • Thermostat is changing the setpoint or mode, like it has a mind of its own!

The good news is that thermostat problems are an easy and affordable fix compared to other problems. During a repair, our expert team at Brody Pennell will check your thermostat first – and get it fixed up, or rule it out as the source of the problems.

2. Air Flow Problems

In a central heating system, warmth transfers from the furnace to the living spaces by way of air. So if air isn’t making it to your space, it’s no wonder you’re feeling chilly. 

There are many causes for airflow problems:

  • Problem with the fan stemming from fan motors, belts, and bearings
  • Trouble with the ductwork, like a blockage or leaks in the ducts
  • Issue with the grilles, vanes, or internal dampers causing unbalanced airflow

No matter the cause, if you have an airflow problem it can cause furnace overheating or poor heating control. One way you can test whether you have an airflow problem is by holding your hand or a piece of tissue up to the supply grilles. The amount of airflow should be about even from any outlet in your home. 

3. Clogged or Dirty Filters

Yes, a clean air filter really does impact the performance of your heater. One of the most common heating problems we see is a dirty, clogged filter. Not only is that bad for your IAQ, but it can seriously impact the energy usage and heat production of your heater. 

Filters are beneficial for keeping the air in your home clean. But left too long without replacing, and they can become an airflow obstruction. Replace your filters every 3 months at minimum. You should replace air filters more frequently if you have a household pet that sheds, or anyone in your household suffers from indoor allergens. 

4. Furnace or Heating System Pilot or Ignition Control Problems

For furnaces that generate heat using natural gas, there is a small flame that is kept lit all the time. We call this the pilot light. When the furnace turns on, it releases gas to the main burner, and the pilot light ignites the gas to provide heat. 

An issue with your pilot light or ignition can cut out heat altogether, or they can cause intermittent heating throughout the home. A reliable contractor with plenty of experience, positive reviews, and industry credentials will be able to spot and repair this problem right away. 

5. Lack of Maintenance

Just like any other important piece of equipment or electronics that you own, your HVAC system and furnace requires maintenance. Skipping on routine maintenance can lead to costly and unexpected breakdowns, and increased energy consumption and bills.

Unfortunately, maintenance is the type of thing you really wish you would have done… once it’s too late. At Brody Pennell, we know Los Angeles homeowners have much more on their mind than scheduling HVAC maintenance. That’s why we have the BPM Club, a membership program which ensures you get your annual AC and heating maintenance along with many other benefits. We’ll be the ones to remember to take care of your equipment, year-round.  

We Can Handle All the Common Heating Problems – And More

Brody Pennell is an established Los Angeles based business, serving our beloved city since 1945. You can bet we have the knowledge and experience to tackle any heating problem – whether it’s one of these common heating problems or a completely different issue. Call us and ask for an opinion – we’re friendly! If you’re ready for honest, old-school service, with the latest training and certifications, call Brody Pennell. Whenever you need us, we’re here.


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2 replies
  • Thank you so much for talking about the pilot light and how important it is to watch it for any problems. This could help me figure out what I need to do since I found something weird with my furnace whenever we use it. The pilot light always flickers and starts acting extremely weird when we use it for more than 10 minutes. When I find an HVAC contractor that can help me out with this, I’ll make sure I tell them about these things I’ve found.

  • It stood out to me when you said that routine maintenance will prevent costly breakdowns and surprising increases in energy costs. My husband and I think it would be smart to get the heating system of our home looked at before the weather gets much colder for peace of mind. Thanks for helping me see why regular repair and maintenance is something we should greater prioritize moving forward!

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