Our furnace has turned on, but wouldn't ignite twice in the past week. When we reset it manually in the breaker box, it works correctly. Any ideas what could be wrong?


There are a couple of parts in a furnace that can either be going bad, or just doing what they were supposed to do due to something happening at that moment. A dirty flame sensor can be intermittent, so cleaning it is essential, or it will become more frequent. Perhaps the pressure switch is going bad, or maybe lousy timing sent a draft down or through the flue, which can trick the switch into thinking it's not getting the right pressure. If that happens more than a couple times in a week (assuming no heavy winds), you may want to replace it before it goes all together. These are common occurrences that are easy to check or fix yourself.

Updated on March 19, 2018

Original Article:

Troubleshooting Common Furnace Problems With an HVAC Expert
By Dan Robbins