Try Our Furnace Troubleshooting Tricks
Furnace won't kick on? We've done the troubleshooting for you. Below, we've listed the top six reasons furnaces stop working.
Do any of these issues and related symptoms match your furnace's problem?
- No power to the furnace - If the fan doesn't respond to raising the thermostat's temperature, a breaker may have tripped, the wiring could be loose, or the furnace switch might be turned off. More complicated problems include trouble with the transformer, thermostat, control board, run capacitor, or blower motor. A technician can perform a diagnostic test to pinpoint the exact problem and come up with a solution.
- Failing motor - You might be able to hear squeaks and squeals from a motor that is about to fail. Immediate attention from a technician is required to save the furnace from breaking down.
- No ignition - In furnaces with spark ignitions, rapid clicking sounds indicate that the burner is trying to ignite. If it can't ignite, there may be a blocked flue, faulty control board, or improper limit control. Repairing or replacing these parts should remedy the problem.
- Main burner problems - Burners that won't stay lit are most commonly caused by dirty flame sensors or-in condensing furnaces-clogged condensate drains. If the burners won't light at all, the gas supply could be cut off. To repair this, our technicians should only need to clean key components and make a few adjustments.
- Issues with the run capacitor or motor - These problems cause the blower not to turn on after the burners ignite. The capacitor can easily be replaced, while motor issues may require a bit more troubleshooting.
- Clogged air filter - Assuming the thermostat isn't set to "on," which keeps the blower motor on continuously, a clogged air filter is the primary cause of a blower motor running all the time. The restricted airflow may have damaged the limit switch, which senses the internal furnace temperature. An Aire Serv technician will not only replace the switch; he or she will also pinpoint the problem. If a clogged filter is the cause, your technician will show you how to change your air filter.