Heil Furnace Not Igniting: Troubleshooting and Repair Guide

The Heil furnace not igniting can leave a home cold and cause unnecessary worry. This guide explains common causes, safety checks, step-by-step troubleshooting, likely repairs, cost estimates, and preventive maintenance to restore reliable heating. It is written for a general U.S. audience and emphasizes safe practices and clear next steps.

Issue	Possible Cause	Typical Fix
Igniter Not Glowing	Faulty hot surface igniter or power issue	Test/replace igniter, check voltage
Pilot Or Flame Failure	Dirty burner, faulty gas valve, or pressure drop	Clean burners, test/replace gas valve
Blower Runs But No Ignition	Control board or safety switch problem	Diagnose control board, replace failed switches
Intermittent Ignition	Thermostat wiring, flame sensor, or loose connections	Clean flame sensor, secure wiring, test thermostat

Why A Heil Furnace Might Not Ignite

When a Heil furnace not igniting happens, the symptom can be no heat, short cycles, or repeated ignition attempts. The ignition process in modern Heil systems typically involves a control board commanding an igniter or pilot, a gas valve opening, and a flame sensor confirming combustion. Failure in any part of this sequence stops ignition.

Common culprits include failed igniters, blocked burners, faulty gas valves, issues with flame sensors, thermostat or wiring problems, and control board or safety switch failures.

Safety First: Before Troubleshooting

Working on gas and electric heating systems carries safety risks. Always turn off power to the furnace at the service switch or breaker before inspecting internal components. If gas smell is present, leave the area immediately, avoid using electrical switches or phones in the house, and call the gas company or 911.

If the homeowner is not comfortable performing basic checks, it is best to call a licensed HVAC technician. Certified pros have the tools and expertise to diagnose gas pressure, combustion, and control systems safely.

Initial Checks A Homeowner Can Do

Start with simple, non-invasive checks to rule out basic causes when a Heil furnace not igniting.

• Thermostat: Verify it is set to heat and the temperature is above room temperature. Replace batteries if cordless models are used.
• Power: Confirm the furnace switch and circuit breaker are on. Some systems have a secondary switch near the furnace often mistaken for a light switch.
• Gas Supply: Ensure the gas valve to the furnace is open. If recent work was done, confirm the home gas service is active.
• Air Filter: A clogged filter can cause safety shutdowns. Replace a dirty filter and retry ignition.

Diagnosing By Symptom

No Ignition Attempts Or No Lights On Controls

If the furnace shows no lights, display, or sound when the thermostat calls for heat, the issue often relates to power or control board problems. Check fuse and breaker, and the low-voltage transformer connections. A dead control board or failed transformer will prevent ignition commands.

Igniter Glows But Gas Does Not Ignite

If the hot surface igniter glows but the burner does not light, suspect the gas valve or a blocked gas path. Technicians will check gas pressure and valve coil operation. A faulty gas valve or insufficient gas pressure will require professional repair or replacement.

Gas Ignites Briefly Then Shuts Off

A flame that appears then goes out often indicates a dirty or failing flame sensor, which cannot detect flame and signals the control board to close the gas valve. Cleaning the flame sensor with fine steel wool or emery cloth can restore proper sensing. Persistent issues suggest replacement.

Repeated Ignition Attempts Or Lockouts

Modern Heil furnaces may enter lockout mode after failed ignition attempts. This prevents continuous gas flow. The control board will need to be reset and the root cause addressed—often a bad igniter, clogged burners, or failing gas valve.

Step-By-Step Troubleshooting

These ordered steps help isolate the cause when a Heil furnace not igniting. Each step is safe for an owner to attempt except where gas or high-voltage testing is required.

1. Confirm thermostat settings and power to the furnace.
2. Replace the air filter and cycle power at the breaker to reset the control board.
3. Observe the ignition sequence: does the inducer motor start? Does the igniter glow? Is there a click of the gas valve?
4. If the igniter does not glow, test for 120/240V (as applicable) at the furnace’s power input and check the 24V control across the gas valve and transformer. If unsure, stop and call a pro.
5. If the igniter glows and burners do not light, suspect the gas valve or supply; confirm the gas shutoff is open and there are no other gas appliances out.
6. If burners light then shut off, remove and clean the flame sensor; reassemble and test.

Common Parts That Fail And How They’re Replaced

Understanding common failing components helps estimate repair complexity and cost when a Heil furnace not igniting occurs.

• Hot Surface Igniter: Fragile ceramic piece that weakens with time. Typical replacement is straightforward and common in most models.
• Flame Sensor: Prone to soot and oxidation. Cleaning often fixes it; replacement is inexpensive and simple.
• Gas Valve: Controls fuel flow. Replacement requires a licensed technician and gas shutdown.
• Control Board/Transformer: Electronics can fail from power surges or age. Board replacement is more expensive and requires proper diagnostics.

Estimated Repair Costs

Costs vary by region and model. These are approximate U.S. ranges for common repairs when a Heil furnace not igniting.

Repair	Typical Cost Range
Igniter Replacement	$150 – $350 (parts & labor)
Flame Sensor Cleaning/Replacement	$60 – $180
Gas Valve Replacement	$400 – $900
Control Board Replacement	$300 – $800

Emergency service, older parts, or complex diagnostics can raise costs. Always request a written estimate and warranty information for parts and labor.

When To Call A Professional

If basic checks do not restore ignition, a professional HVAC technician should be called. Call a pro if there is a gas smell, if tests require gas pressure measurement, or if electrical diagnostics are necessary.

Licensed technicians will check gas pressure, test control voltages, perform combustion analysis, and ensure safety controls and venting are functioning correctly. They can also diagnose intermittent electrical faults and replace sealed components safely.

Preventive Maintenance To Avoid Ignition Problems

Regular maintenance lowers the chance of a Heil furnace not igniting. Typical maintenance includes annual professional tune-ups and seasonal homeowner checks.

• Schedule an annual inspection and tune-up before heating season to clean burners, inspect heat exchangers, and test safety controls.
• Replace air filters every 1-3 months depending on use and filter type.
• Keep the area around the furnace clear and ensure proper venting and intake airflow.
• Observe flame color: a healthy flame is mostly blue. Yellow or flickering flames can indicate combustion issues and require immediate attention.

Parts Sourcing And Compatibility

When replacing parts on a Heil furnace not igniting, verify part numbers against the furnace model and serial number, usually on the furnace data plate. OEM parts from Heil or authorized distributors typically ensure compatibility and maintain warranty coverage.

Aftermarket parts may be cheaper but confirm they meet the same specifications. For electronic control boards, firmware revisions can be important, so technicians often prefer OEM replacements.

Frequently Asked Questions

How Long Does A Typical Igniter Last?

Hot surface igniters commonly last between 3 to 10 years depending on cycles and brand. Signs of failure include visible cracks or the igniter not glowing even with proper voltage.

Can A Dirty Filter Cause Ignition Failure?

Yes. A clogged filter can cause pressure and airflow safeties to engage, preventing the furnace from proceeding to ignition.

Is It Safe To Keep Trying The Thermostat If The Furnace Is Locked Out?

Repeated attempts can extend lockout periods and waste gas if a valve sticks. It is better to diagnose the cause rather than repeatedly cycling the thermostat.

Does The Thermostat Often Cause Ignition Problems?

Thermostats can cause problems if wiring is loose, settings are incorrect, or low-voltage terminals are damaged. Simple wiring checks and replacing batteries often resolve thermostat-related issues.

Troubleshooting Checklist For Technicians

• Verify model and obtain error codes from the control board LED or display.
• Measure incoming power and control voltages to the transformer and gas valve.
• Inspect igniter visually and test resistance with a multimeter.
• Check flame sensor condition and clean or replace as needed.
• Perform gas pressure test and check for proper manifold pressure during ignition.
• Inspect vent and inducer operation for proper draft and obstruction.

Key Takeaways

When a Heil furnace not igniting, homeowners should first perform safe, basic checks: thermostat settings, power, filters, and visible igniter condition. If those checks fail, the most common causes include a failed igniter, dirty flame sensor, faulty gas valve, or control board issues. Professional diagnosis is required for gas pressure, combustion, and electrical control problems.

Timely preventive maintenance, correct part selection, and working with licensed HVAC professionals reduce downtime and repair costs while improving safety and efficiency.