Why is my gas furnace making a scary 'boom' noise?  Pippin Brothers, Lawton, OK
December 3, 2010

When your furnace isn’t working correctly, or just stops heating your home altogether, don’t panic. It’s probably not the furnace itself that is failing; it’s likely something else causing the furnace not to work. 

Every heating season, we get hundreds of calls from people complaining about problems with their furnace. We’ve collected the most common complaints we hear and listed them along with information explaining what might be causing them. 

Problem: Furnace Isn’t Heating

Possible Causes:

  • Thermostat – This can often be an embarrassing cause of furnace failure. Customers will call for service only to have a technician check the thermostat and see that it isn’t set correctly. Make sure it is switched to “heat,” the desired temperature is higher than the existing room temperature and the fan is set to “auto.” If you have a programmable thermostat, you may need to override the settings to verify whether the thermostat is causing the problem or not.

  • Circuit Breaker – Check your circuit breaker. It could be tripped or blown and keeping your furnace from turning on.

  • Faulty Pilot Light – This is a common problem that can become quite frustrating when you don’t know why it’s happening. A pilot light can go out for a number of reasons. It could be caused by a faulty thermocouple or dirty gas tube and even a draft. If you suspect a problem with your pilot light, it’s best to contact a professional to help diagnose and repair the problem.

  • Natural gas or propane flow is inhibited. This can sometimes happen when the gas pressure regulator malfunctions and closes off the gas feed or the valve has simply been closed off. If you suspect either of these scenarios, don’t try to troubleshoot it yourself. It’s safest to leave this to a trained professional.

Problem: Not Enough Heat

Possible Causes:

  • Dirty Air Filter – Dirty furnace filters clogged with dust, pet hair and other debris will inhibit the flow of air over the heat exchanger and make warming your home more difficult. Make sure you change your air filter every one to three months, depending on the variety.

  • Imbalanced airflow – If it doesn’t matter how often, and at what temperature, you run your furnace, some rooms never seem to be warm enough, it could be the airflow. In this case, it isn’t the furnace at all. To determine if this is the problem, you should have a full airflow analysis, correction and balancing.

  • Leaky Ducts – Cracks, broken seals, and even poor insulation in your ductwork can permit warm air to escape, which makes it very difficult to keep your home warm. If you suspect this is a problem consider having your ducts professionally inspected and sealed or insulated.

Problem: High Energy Bills

Possible Causes:

  • Lack of Maintenance – Of all the furnace problems, a lack of furnace maintenance is the biggest culprit. When it comes to efficiency, a well-maintained furnace will always outperform its dirty, out of tune counterpart. You should plan on having your furnace professionally cleaned and maintained at least once a year to maximize on efficiency and performance. Units that run efficiently use less energy. When you are using less energy, you’re spending less money.

  • Unit is Past Its Prime – Efficiency, efficiency, efficiency. Today’s newer furnaces operate much more efficiently than the older units of yesterday. If your unit is older than 15 years, you should consider purchasing a new furnace. The savings over the long run will outweigh the cost of the upgrade.

If you are having problems with your furnace and you suspect one of these possible causes listed below, it’s always best to contact a trained professional HVAC technician to help you verify your suspicions and make the best suggestions for improvement. Pippin Brothers is Lawton’s leading HVAC specialist. Contact us online today to learn how we can help you.