Furnace Won't Start in Dallas? Try These Fixes First

When your furnace won't start, it's often something simple like a tripped breaker, thermostat setting, or safety switch. This guide from Dallas Heating and Air Conditioning walks you through systematic troubleshooting before calling for furnace repair service. You might save yourself a service call.

Quick Checks Before Calling for Service

The thermostat is the most common reason a furnace won't start. Verify the mode is set to HEAT (not Cool, Off, or Auto) and the set temperature is at least 5 degrees above current room temperature. Even if the display works, replace the batteries because weak batteries cause issues.

Problems Requiring Professional Service

Failed Igniter

The hot surface igniter is the most common component failure in modern furnaces. Your furnace can't light the burners, so you hear the furnace attempt to start (whooshing sound from the inducer fan) but no ignition occurs. You may see an error code blinking on the furnace.

After 8-9 months of sitting idle, dust accumulates on igniters in North Texas homes, making startup failures common when you first turn on heat in November. Igniter replacement requires furnace disassembly, and the igniter is fragile. Professional service costs $150-$300.

Flame Sensor Failure

The flame sensor verifies burners are lit. When faulty, it can't confirm flame presence, so your furnace shuts down as a safety precaution. Burners light briefly (you see flame through the window), then the flame goes out after 3-10 seconds. The cycle repeats continuously.

The sensor may just need cleaning or may need replacement. Other issues can cause similar symptoms, so proper diagnosis matters. Service costs $80-$200.

Draft Inducer Motor Failure

The inducer motor creates draft for safe combustion and must run before the gas valve opens. When it fails, you hear complete silence when the furnace should start, or unusual motor sounds like grinding or squealing. There's no whooshing sound that normally precedes ignition.

The technician must diagnose whether it's the motor, capacitor, or control board. This is a safety-critical component. Repair costs $300-$600.

Control Board Failure

The furnace control board coordinates the startup sequence. When it fails, the system can't respond to thermostat calls. You'll see no response at all, error codes blinking, or erratic behavior. This is often diagnosed after ruling out other causes.

Board replacement is expensive, so correct diagnosis matters. The technician must match the replacement board to your furnace model. Repair costs $250-$600 including the board and labor.

Gas Valve Failure

The electronic gas valve won't open, so your furnace has power and the inducer runs, but no gas flows and no ignition is possible. You hear normal startup sounds but no ignition, there's no gas smell when the furnace attempts to start, and other gas appliances in your home work fine.

This is a gas component requiring proper diagnosis to verify it's the valve and not a control signal issue. Repair costs $250-$500.

Emergency Situations

Call immediately and evacuate if you smell gas. Call from outside and contact your gas company. If your carbon monoxide detector alarms, leave your home and call 911. For electrical burning smell, visible smoke, or sparks, turn off power at the breaker and call immediately.

During freezing temperatures with no heat, call for emergency service to prevent frozen pipes. Water damage from frozen pipes far exceeds the cost of after-hours HVAC service.

Professional Service You Can Trust

When you need service, call Dallas Heating and Air Conditioning at (214) 710-2515. Our EPA-certified technicians serve Dallas, Plano, Frisco, McKinney, Allen, Richardson, Carrollton, The Colony, and Lewisville with same-day and emergency service available.

We've served North Texas for over 20 years and hold an A+ BBB rating. We understand the unique challenges furnaces face after sitting dormant through our long cooling seasons. We'll diagnose your furnace quickly and get your heat running.