Why Won’t My Furnace Stay On?
Nothing quite compares to the frustration of a furnace that keeps turning off by itself, especially when the chilly Dallas winter creeps in. You expect steady warmth, but instead, your furnace flickers on only to shut down again moments later. This scenario is all too common.
Fortunately, a little troubleshooting is often all it takes to fix this problem. Consider the most common reasons why your furnace won’t stay on, what you can try, and when it’s time to call Harris Air Services for help.
Common Reasons Your Furnace Won’t Stay On
If your furnace refuses to complete a full cycle, you’re dealing with short-cycling. Here are a few common culprits behind a furnace that won’t stay lit and what you can do about them.
Dirty Air Filter
The furnace air filter catches airborne particles and eventually becomes clogged. This restricts airflow, causing your furnace to overheat and shut off as a safety measure. Open the air filter panel and take a look inside. If the filter is dirty, replacing it could solve the problem right away.
Thermostat Issues
Your furnace may not stay on if your thermostat is acting up. First, double-check that the thermostat is set to “heat” and the temperature is high enough to trigger the furnace. Check and replace the batteries, if needed, and look into having the unit moved if it’s installed near heat-generating appliances or in direct sunlight.
Blocked Vents or Registers
Poor airflow from blocked or closed vents could be to blame for your furnace shutting off prematurely. Furniture, rugs, or drapes might also be obstructing the flow of warm air. To prevent these issues, make sure all your vents are open and unblocked.
Pilot Light or Ignition Issues
If your furnace won’t stay lit, you could be dealing with a faulty pilot light or ignition system. For a pilot light furnace, try relighting it by following the manufacturer’s instructions. If it won’t stay lit, the thermocouple might need cleaning or replacement. For newer models with electronic ignition, you’ll need to schedule a professional repair.
Resetting Your Furnace
Furnaces can get stuck in an error mode if there’s a temporary glitch, and resetting the system may resolve the issue. First, locate the reset button (check the manual if needed). Turn off the furnace, wait a few minutes, and press the reset button. If the furnace keeps short-cycling after this, it’s time to call a professional.
Faulty Limit Switch
A limit switch is a safety feature that shuts off the furnace when it gets too hot. If the switch is faulty, it may shut down your furnace even when it’s not overheating. Unfortunately, this situation requires calling a pro.
Oversized Furnace
If you’ve ruled out everything else and your furnace still keeps turning off, the system could be oversized. When the furnace is too powerful, it constantly short cycles, causing wear and tear and persistent comfort issues. There’s no easy fix for this. You’ll need to consult an HVAC professional to find out whether your furnace is correctly sized.
When to Call Harris Air Services
Call us for furnace repair if:
- The pilot light keeps going out, or the electronic ignition system isn’t working.
- Your furnace continues to short-cycle despite checking the air filter, thermostat, and vents and resetting the system.
- You suspect a faulty limit switch or another electrical issue.
- You smell gas or suspect a leak. In this emergency, turn off your furnace and call a professional immediately.
- Your furnace is oversized and keeps short-cycling.
Remember, attempting DIY furnace repair is dangerous and could void the warranty. When in doubt, call in the pros.
Get Reliable Furnace Repair from Harris Air Services
If your furnace keeps turning off and you’ve tried troubleshooting without success, Harris Air Services is ready to help. Locally owned since 2008, we provide prompt, professional furnace repair for homeowners in McKinney, Allen, Plano, Frisco, Prosper, and beyond. Honest pricing, customized maintenance plans, and same-day service make us “Simply the Best.”
Contact us today to schedule furnace repair in the McKinney area.
