If your Rheem furnace has a blinking or flashing light, you’re likely dealing with some heating problems—possibly on the coldest night of the year. You’re not alone. I’ve helped dozens of homeowners around Steubenville, Ohio, figure out what their blinking green or red light means and how serious the issue really is.
In this article, you’ll learn:
- What the blinking or flashing light on your Rheem furnace means
- How to decode common Rheem furnace LED codes
- When to fix it yourself vs. when to call a pro
- What it might cost to repair
Why Your Rheem Furnace Has a Blinking Light
All Rheem furnaces are equipped with a diagnostic LED light, usually found on the control board inside the furnace cabinet. That blinking or flashing light is actually trying to help you: it’s telling you what’s wrong.
The number of blinks corresponds to a fault code. These codes could be telling you that the ignitor failed, the pressure switch is stuck, or something more serious like a control board issue.
Real Story from Alex: Just last winter, a homeowner in Weirton called us because their Rheem Classic 90 Plus furnace wouldn’t turn on. The green LED was blinking three times. We traced it back to a dirty flame sensor, which we cleaned on-site. Their heat was back in under an hour—no parts needed.
Common Rheem Furnace Blinking or Flashing Light Codes (And What They Mean)
Below are some of the most frequent LED codes seen on Rheem furnaces:
1 Flash: Ignition failure. Likely causes include a failed ignitor or malfunctioning gas valve.
2 Flashes: Pressure switch stuck closed. This could be due to a clogged vent or faulty switch.
3 Flashes: Pressure switch stuck open. Could point to a blocked flue, failed inducer motor, or drain issue.
4 Flashes: High limit switch open. Often triggered by dirty furnace filters or restricted airflow.
5 Flashes: Flame detected when no flame should be present. Inspect the gas valve and control board.
6 Flashes or More: These indicate serious control board or lockout issues. Professional service recommended.
Pro Tip: Count the blinks—they repeat in a pattern. Then match the code using your furnace manual or the diagram inside the access panel.
DIY Fixes vs. Professional Repairs
Safe DIY Fixes:
- Replace or clean your furnace filter
- Clean the flame sensor using emery cloth
- Power-cycle your furnace or press the reset button (if equipped)
Call a Pro If:
- The code references a pressure switch, control board, or gas valve
- The furnace enters a hard lockout or keeps shutting down
- You smell gas, hear clicking with no ignition, or suspect electrical damage
Important: Never troubleshoot gas or electrical components unless you’re licensed and trained. When in doubt, call Honest Fix.
Common Rheem Furnace Repair Costs
Based on our work across Steubenville and surrounding areas:
- Flame sensor service/replacement: $90 – $180
- Hot surface ignitor replacement: $180 – $320
- Pressure switch replacement: $220 – $450
- Furnace control board replacement: $450 – $1500
These are estimates. If you’re near Steubenville, Honest Fix can provide a free exact quote with no pressure to commit.
Alex’s Advice: In 20+ years of HVAC work, I’d say 7 out of 10 blinking light calls are fixed by cleaning or maintenance. Get your furnace tuned up annually and save yourself the worry.
Frequently Asked Questions
What does it mean when my Rheem furnace light is blinking 3 times? That usually means the pressure switch is stuck open. Causes include vent blockages, a failed inducer fan, or condensate issues.
How do I reset my Rheem furnace? Turn off power to the furnace at the switch or breaker, wait 30 seconds, then turn it back on. If there’s a reset button near the blower or board, press it.
Can I fix a Rheem furnace flashing light myself? Sometimes. If it’s a dirty filter or flame sensor, yes. But anything involving gas or electronics should be handled by a professional.
Why is my Rheem furnace light blinking but the heat won’t come on? The blinking light is showing a fault. Count the flashes, look up the code, and that’ll tell you why your furnace isn’t starting.
Your Next Steps
If your Rheem furnace light is blinking:
- Count the LED blinks and find out what they mean.
- Try safe fixes like cleaning the flame sensor or changing the air filter.
- If it doesn’t resolve the issue, call Honest Fix for a free exact quote.
Want to avoid this next winter? Schedule your annual furnace maintenance.
We service Steubenville, Weirton, Wintersville and surrounding area.
