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Common Furnace Problems and How to Fix Them

Posted by Kelly on Nov 3, 2015 3:20:22 PM


If you own a furnace, chances are at some point in its lifespan you are going to need to call a pro to make a repair or two. But the type of repair depends on how well you maintain your furnace. That’s why we’ve put together this list of the most common furnace problems and how to fix them! 

Common Issues Of An Improperly Maintained Furnace

If you don’t get annual maintenance checks or change your filter regularly, you’ll likely be a making a call to an HVAC technician a lot more often than you’d like. Some of the more common culprits that cause an improperly maintained furnace to go out are:

  • Dirty Filters – Can limit airflow and make your furnace work harder in order to heat your home. That extra work can lead to mechanical and electrical parts going out a lot sooner than normal. Bad airflow can lead to lots of damage. Change it at least four times a year.
  • Dirty, Corroded Coils – If moisture or soot get into your HVAC system, that can lead to rust and corrosion, which means replacing parts more often. Get regular inspections to prevent this.
  • Faulty Thermostat – If you’re not hiring a pro for annual maintenance and cleaning, you may see issues with your furnace cycling on and off or not getting as warm as you’d like it in your home. A technician will be able to see if there is a problem with the fan, limit switch, or just a faulty thermostat. Some digital thermostats may just need the batteries replaced.

Common Issues Of A Well Maintained Furnace

Even people who take great care of their furnace will still need to call for repairs – just not as frequently or as soon as those who don’t take good care of their system. But, just because you have regular maintenance checkups and change your filter regularly doesn’t mean you’re free from furnace fixes. Parts wear out over time, and because a well maintained HVAC could possibly last longer than expected, you will likely need to replace some parts on your HVAC rather than replace the whole unit.

Our resident expert, Keith Hill, technical support manager at Minnesota Air, says that in a properly maintained furnace, the most common problems will be with the ignition system.

“Ignition system components typically will not last the life of the furnace (15 to 20 years), but there is not much a homeowner can do to extend their life,” he says. “My advice would be to proactively change these components after the furnace reaches 8 to 10 years of age.”

He says the best time to do this would be when you are already getting your annual maintenance check and inspection.

Another common issue can happen because of a problem with the draft inducer – sometimes called a power venter. The draft inducer draws the combustion byproducts out of the furnace and pushes it into the vent system.

“Many will last the life of the furnace, but it’s not unusual to see trouble at 10 to 15 years. Many times there are warning signs – usually it’s noise or vibration,” he says.

Finally, Keith says the blower motor is another component that may not make it to the 20-year mark.

“Again, noise or vibration may be an indicator of pending failure,” he says. “On this one, the homeowner can extend the life by running the blower continuous in ‘ventilation’ mode or ‘fan on.’ It may seem counterintuitive, but a motor suffers the most wear and tear when it starts. A continuous operating motor will last much longer than one that starts and stops with each cycle of the furnace.”

Keith says that if the cost of running the fan continuously is a concern, there are furnaces with electronically controlled high efficiency (ECM) motors. That can help the electric bill go down, but even the extra power used on a standard furnace isn’t significant enough to most people.

“These motors can also be retrofitted into an existing furnace,” he says. “This is not a D-I-Y project – call a pro for this upgrade.”


Topics: Heating