Waking up to find your Las Vegas home’s air conditioner won’t turn on is incredibly frustrating. When both your heating and cooling systems are unresponsive, it usually points to a shared problem within your HVAC system, like a power supply issue or a thermostat malfunction. 

But don’t panic just yet! We’ve put together a clear, 5-step troubleshooting guide to help you diagnose common issues yourself before you need to call in the professionals.

Air Conditioner Won’t Turn On? Easy Checklist for Homeowners in Las Vegas

1

Check the Thermostat

Your thermostat is the core of your HVAC system. If it’s not working properly, neither will your air conditioner or heater.

Problem: Is the thermostat blank? This is often a sign of dead batteries.
Solution: Replace them with fresh ones, even if you think they might still have some life left. This is a quick and easy fix that often resolves the issue.
Problem: Is the screen on, but nothing is happening?
Solution: Double-check your thermostat settings. Ensure it’s set to “Heat” or “Cool” (whichever you’re trying to use) and not “Off.” Also, make sure the fan setting is on “Auto” rather than “On” for normal operation.
2

Check the Circuit Breaker for Your AC System

💡 Pro Tip from Bob’s Repair

Our technicians often find that breakers for HVAC systems installed in older Las Vegas homes are more sensitive to power fluctuations during peak summer usage. If you find your breaker trips frequently on hot afternoons, it’s a sign your system is straining and needs a professional inspection.

A tripped circuit breaker is one of the most frequent reasons for an HVAC system not turning on. Your HVAC system typically has dedicated breakers in your main electrical panel.

  • Locate your home’s main electrical panel.
  • Look for breakers labeled “HVAC,” “Furnace,” “Air Handler,” or “Air Conditioner.”
  • See if any of these breakers are in the “tripped” position (usually halfway between “On” and “Off”).
  • To reset a tripped circuit breaker, firmly push it to the “Off” position, then firmly push it back to the “On” position.
Important Safety Note: If the circuit breaker immediately trips again after you reset it, do not attempt to reset it a second time. This indicates a more serious electrical problem or an issue with your AC unit itself that requires an HVAC professional. Angi warns that repeatedly resetting a tripping breaker can cause further damage or create a fire hazard.
3

Check All HVAC Power Switches for Electrical Issues

Beyond the main circuit breaker, your HVAC system has other power switches that might have been accidentally turned off, preventing it from turning on.

Indoor Unit Power Switch: Near your indoor furnace or air handler unit (often in a utility closet, basement, or attic), there’s typically a standard light-switch-style power switch mounted on or near the unit. Ensure this switch is in the “On” position.
Outdoor Disconnect Box: For your AC unit, there’s also an electrical disconnect box located near the outdoor unit. This box usually contains a pull-out block or a switch. Verify it’s in the “On” position.
4

Air Filter Maintenance: A Common Reason for AC Issues

A severely clogged or dirty air filter can significantly restrict airflow to your HVAC system. This can cause the furnace or AC unit to overheat, activating a safety switch that shuts the entire system down to prevent further damage.

  • Locate your air filter (usually in the return air duct or within the air handler unit itself).
  • Pull out the filter and inspect it. If it’s covered in a thick layer of dust and debris, it’s time for a replacement.
  • Replace a dirty air filter with a clean one. Even if it’s not the primary cause of your current issue, regular air filter maintenance is crucial for optimal performance and efficiency of your heating system and air conditioning, especially for an older furnace.
  • In a climate like Las Vegas, fine dust and sand can be a major factor, causing air filters to clog faster than in other regions.
5

Check the Condensate Overflow Switch

Your indoor AC system unit produces condensation during the cooling process, which drains away through a condensate line. Many systems have a safety switch in the drain pan that shuts the entire system down if the drain line becomes clogged and the pan starts to overflow with water.

  • Locate the drain pan near your indoor air handler or furnace.
  • Look for standing water in the pan. If there’s water, the condensate line might be clogged.
  • Clearing a minor clog can sometimes be a DIY fix, but if the problem persists or you’re unsure, it’s best to call a certified licensed professional.

Still Having Issues? We’re Here to Help!

If your AC still won’t turn on after following these steps, it’s time for professional help. Our NATE-certified technicians are available 7 days a week to get your system running again.

Contact Bob’s Repair Request an Appointment

When It’s Time to Call a Professional to Fix Your Air Conditioning That’s Not Blowing Cold Air

outdoor AC Unit alt

If you’ve carefully gone through all five steps in this checklist and your HVAC system is still unresponsive, the issue is likely more elaborate and internal. At this point, it’s crucial to call an HVAC professional for a safe and accurate diagnosis. Most air conditioning and heating issues need to be resolved by a professional to prevent further damage and ensure safety.

Issues that typically require an expert include:

  • Failed Transformer or Control Board: These electrical components are vital for your system’s operation.
  • Blower Motor Issues: If the fan isn’t turning, it could be a problem with the blower motor.
  • Faulty Wiring: Loose or damaged wiring can cause a complete system shutdown.
  • Refrigerant leaks: If your air conditioner is blowing cold air but not consistently, or your system isn’t cooling, refrigerant leaks could be the problem. Leaks can cause low refrigerant levels.
  • Compressor issues: The compressor is the heart of your AC unit.
  • Gas furnace issues: Problems with the pilot light, flame sensor, or gas line for a gas furnace require specialized knowledge.

Still Uncomfortable? Contact Bob’s Repair Today!

By following this 5-step checklist, you’ve taken proactive steps to diagnose why your HVAC system won’t turn on. If you’ve completed this troubleshooting and your HVAC system is still dead, it’s a clear sign that professional expertise is needed. The team at Bob’s Repair is available for emergency service to diagnose the problem accurately and restore comfort to your home. We’re here to help!