Fixing a Low Stage Pressure Switch Stuck Open

If you've just looked at your furnace's diagnostic light and realized your low stage pressure switch stuck open, you are probably feeling a mix of frustration and cold. It's one of those issues that always seems to pop up at 11:00 PM on a Friday night when the temperature is dropping. Dealing with a furnace that won't kick on is stressful, but the good news is that this specific error doesn't always mean you need a brand-new system. Most of the time, it's a sign that the furnace is trying to protect you from something much worse, like exhaust fumes leaking into your home. ...

February 16, 2026 · 7 min · Zambrano Defever