Furnace
Furnace Will Not Ignite in Ontario
Understanding Why Your Furnace Will Not Ignite
A gas furnace follows a controlled startup sequence. On many modern systems, the draft inducer starts first, and a pressure switch confirms the required draft condition before ignition begins. The igniter then heats or sparks, the gas valve opens, and the control board checks for flame. If a required condition is missing, the furnace stops or retries. We identify where that sequence breaks down, using the furnace's fault history, electrical measurements, and manufacturer instructions to separate the actual failure from the symptoms it creates.
No ignition is different from a flame that lights briefly and then disappears.
Service Inclusions
- ✓ Ignition sequence diagnosis
- ✓ Igniter and flame sensor testing
- ✓ Venting and pressure switch checks
- ✓ Repair options explained
Typical price range
$200 to $900
Typical Ontario price range before tax. Your actual price depends on your equipment, parts and access, and is confirmed after we assess the job.
Get a tailored estimate →Clues From the Startup Sequence
Inducer runs, but nothing lights
A small motor starts, yet the igniter stays dark. The furnace may be waiting for draft confirmation, or an electrical fault may be preventing the ignition stage.
Igniter glows without a flame
A visible glow without burner ignition can point to gas delivery, valve control, or igniter positioning issues. Observation alone cannot confirm which component needs attention.
Burners light and quickly stop
Brief ignition followed by shutdown often involves flame proving, but grounding, burner condition, or gas pressure can contribute. We test before treating it as a sensor problem.
Repeated attempts end in lockout
Clicks, short startup attempts, and a flashing diagnostic light can indicate ignition lockout. Record the displayed code without opening the burner compartment or repeatedly resetting the furnace.
Stop for These Safety Warnings
If you smell gas, leave the home and call the gas utility or 911 from outside. Do not operate switches, use a flame, or try another furnace reset. A carbon monoxide alarm also means leaving immediately and calling 911. Without those warning signs, avoid bypassing safety switches or manually lighting burners. A bang at ignition, soot, or visible scorching warrants stopping furnace operation and arranging professional assessment before further use.
Checks You Can Make Without Opening the Furnace
Confirm the thermostat is set to heat
With a temperature above the current room reading.
Check that the furnace switch is
On and the access panel is properly seated; do not remove it during operation.
Inspect an accessible filter
And replace it if needed, recognizing that a filter change may not resolve an ignition fault.
From ground level, look for snow covering exterior intake
Or exhaust openings; avoid dismantling pipes or reaching into them.
Tracing the Failure Before Replacing Parts
- 01
sounds, fault codes, whether a flame appears
And when the problem began.
- 02
Check thermostat demand
Check thermostat demand, power, safety circuits, venting, and condensate drainage as applicable to your furnace.
- 03
Test the ignition components
Gas valve command, and flame signal where the startup sequence indicates a fault.
- 04
Explain the findings
Explain the findings and proposed repair, then verify ignition and heating operation after approved work.
Factors That Shape Your Repair Quote
Diagnostic complexity
An intermittent ignition failure may require more investigation than an accessible failed component.
Repair requirements
Igniter replacement, wiring correction, gas valve work, and vent or drainage repairs involve different labour and parts.
Equipment and access
Furnace design, component availability, working clearance, and urgent scheduling can affect the quote.
We aim to leave you with a clear explanation of what stopped ignition and why the recommended work addresses it. Our checks follow the startup sequence, which helps avoid replacing unrelated components. After a repair, we verify that the burners light and remain established through the relevant operating checks rather than relying on a single successful start.
Choose HeatNest for Clear Diagnostic Answers
HeatNest is a North York home heating, cooling, and gas company serving homeowners who need practical answers. Tell us whether your furnace is silent, clicking, glowing, or briefly lighting. Those details help us prepare for the visit. We explain what we can establish remotely, what needs on site testing, and which concerns require immediate safety action.
Sequence based troubleshooting
We follow the furnace's actual startup behaviour to narrow the fault instead of assuming every ignition problem needs an igniter.
Clear repair discussions
We explain the failed condition, proposed work, and relevant cost factors so you can assess the recommendation before approving repairs.
Model specific assessment
We use equipment details and manufacturer guidance because ignition designs, diagnostic codes, and test procedures differ between furnace models.
Attention to underlying causes
We consider drainage, draft, wiring, and operating conditions when they may explain why an ignition component is not working.
Serving North York and Surrounding Communities
From our North York base, we serve Toronto, the GTA, and Ontario communities with heating, cooling, and gas service. Contact us with your address to confirm coverage and scheduling for your location. For a furnace ignition problem, mention that you currently have no heat.
Acton · Adjala Tosorontio · Ailsa Craig · Ajax · Angus · Arva · Aurora · Aylmer · Ayr · Barrie · Bolton · Bowmanville · Bradford · Brampton · Brantford · Brooklin · Burford · Burlington · Caledon · Cambridge · Clarington · Collingwood · Courtice · Delaware · Dorchester · Dutton · East Gwillimbury · East York · Enniskillen · Erin · Etobicoke · Exeter · Fort Erie · Georgetown · Georgina · Glencoe · Grimsby · Guelph · Halton Hills · Hamilton · Hensall · Ilderton · Ingersoll · Innisfil · Keswick · Kilworth · King City · Kitchener · Komoka · Lincoln · London · Lucan · Markham · Midland · Milton · Mississauga · Mitchell · Mitchell Corners · Mono · Mount Brydges · New Tecumseth · Newcastle · Newmarket · Niagara Falls · Niagara on the Lake · Nobleton · North York · Norwich · Oakville · Orangeville · Orillia · Oro Medonte · Orono · Oshawa · Ottawa · Parkhill · Pelham · Pickering · Port Colborne · Port Stanley · Puslinch · Richmond Hill · Scarborough · Schomberg · Scugog · Shedden · Smithville · Springwater · St. Catharines · St. Marys · St. Thomas · Stratford · Strathroy · Sutton · Thamesford · Thorndale · Thornhill · Thorold · Tillsonburg · Toronto · Tottenham · Tyrone · Unionville · Uxbridge · Vaughan · Wasaga Beach · Waterloo · Welland · Whitby · Whitchurch Stouffville · Woodstock
Questions About Failed Furnace Ignition
+Should I keep resetting a furnace that will not ignite?
No. Repeated resets can erase useful fault information and restart a sequence that is stopping for a reason. Record the code and describe what happens during startup. Follow the owner's manual for any permitted reset, and stop if the failure returns.
+Does a glowing igniter mean the gas valve is bad?
Not necessarily. A glowing igniter does not prove that the valve is receiving the correct command or that gas supply conditions are suitable. Igniter performance and burner alignment can also matter. We test the relevant conditions before recommending a gas valve replacement.
+Can a dirty flame sensor prevent ignition?
A flame sensor usually proves flame after the burners light. If the furnace lights and quickly shuts down, flame sensing is one possibility. If no flame appears at all, we investigate earlier stages of startup rather than assuming sensor cleaning will solve it.
+Can you help with an urgent no heat call?
Call us with your location and the furnace symptoms so we can discuss current scheduling and urgency. Tell us if vulnerable occupants are affected or the home is cooling quickly. Do not heat the house with an oven, barbecue, or outdoor fuel burning equipment.
+Will I need a replacement furnace?
An ignition failure alone does not establish that replacement is necessary. We assess the fault, equipment condition, parts availability, and any safety concerns. If repair and replacement are both reasonable options, we explain the tradeoffs so you can request the appropriate quote.
+What information should I have ready when calling?
Have your address, furnace make and model if accessible, and any displayed fault code ready. Describe whether you hear the inducer, see an igniter glow through a viewing window, or notice a brief flame. Do not remove panels to gather this information.
What customers say about our furnace will not ignite
"Called in the morning, had someone here by mid afternoon. Friendly, careful and professional from start to finish."
"Great communication, I got a heads up before arrival and a clear summary of the work afterwards."
"The technician showed up on time, explained exactly what was wrong and had everything working the same afternoon. No upselling, just honest work."
Request Help Getting Your Heat Back
If your furnace will not ignite, call HeatNest at (289) 801-7262 to discuss the symptoms and request a quote. We will help clarify the next step, confirm service availability for your area, and explain how an on site diagnosis can guide the repair.