Furnace Won’t Ignite? 7 Checks Before You Call
Pittsburgh winters can turn fast, especially along the rivers and our hilltop neighborhoods. If your furnace won’t ignite, the house cools quickly and stress rises even faster. Before you call Mitchell Plumbing, Heating and Cooling, here are safe things you can observe and share with a technician. This helps us resolve the issue faster and gets heat back to your family.
If you prefer, you can skip ahead and request service now. Explore our furnace services and book a visit with a friendly pro from Mitchell Plumbing, Heating and Cooling.
Why Furnaces Won’t Ignite In Pittsburgh, PA
Cold snaps in neighborhoods like Squirrel Hill, Shadyside, and Mt. Washington can expose weak spots in a heating system. High-efficiency units with outdoor PVC vents sometimes struggle after heavy, wet snow. Older Pittsburgh homes may have drafty basements that affect combustion air. Common ignition problems include a worn igniter, a dirty flame sensor, safety lockouts after repeated failed starts, or blocked intake and exhaust.
Every make and model protects itself with safeties. If something looks risky, the control board prevents ignition to keep you safe. That’s good, but it can also leave you wondering what to do next.
What To Gather Before You Call Mitchell Plumbing, Heating and Cooling
Sharing clear observations helps a technician arrive prepared. You don’t need tools or to remove panels—just note what you see, hear, or smell.
- Model number from the label on the outside of the cabinet, if visible.
- Thermostat screen status (heat, temperature setting, battery icon, any alerts).
- Any blinking lights or error codes visible through a window on the furnace door.
- Unusual sounds at start-up, like a brief hum, click, or a fan that stops and starts.
- Recent filter change date and whether airflow feels weak at the vents.
- Weather notes: drifting snow in Lawrenceville alleys or icy conditions in the South Hills.
If you smell gas, leave your home and call 911 or your gas utility. Safety comes first, always.
Seven Safe Checks Without Tools
These are look-and-listen checks only. Do not open the furnace cabinet or attempt repairs. Your notes guide our technician and may shorten the diagnostic time.
1) Thermostat Display And Mode
Stand at the thermostat and look at the screen. Is it lit? Is “heat” showing and the setpoint above the room temperature? If the screen is blank or showing a low-battery icon, make a note. Also note if the thermostat recently updated or was changed to a schedule that may delay heating.
2) Furnace Status Light
Many units have a small viewing window on the front panel. Without removing any screws, look for a steady or blinking light. A repeating blink pattern often points to a specific lockout. Take a quick photo so you can share it with our team.
3) Airflow And Filter Clues
Low airflow can prevent ignition or cause the furnace to shut itself down. Put your hand near a supply register. Does the airflow feel weak compared to normal? Think back to the last time the filter was changed and note it for the technician.
4) Outdoor Vents After Snow Or Ice
High-efficiency furnaces exhaust through PVC pipes that exit a side wall. After lake-effect-like bands that sometimes sweep across the North Hills, snow can drift against those pipes. Look from a safe distance for packed snow, ice, or frost near the terminations. Do not try to chip or reach inside.
5) Sounds At Start-Up
When heat is called, you might hear a small fan (inducer) start, then a click, then ignition. If you hear the fan but never feel warmth, or the fan starts and stops, make a note. A brief buzz from a condensate pump near the furnace can also be a helpful clue.
6) Odors Or Visual Cues
A faint metallic or hot-dust smell after long downtime can be normal for the first cycle. A sharp electrical smell, continuous smoke, or soot marks at the cabinet are not. Record what you notice and turn the system off at the thermostat.
Some systems allow a simple reset after a lockout, but resets without a fix usually fail again. Do not keep pressing any reset button. Repeated tries can trigger deeper lockouts and delay heat. Tell us if anyone pressed reset and how many times so we can plan the right approach.
What Might Be Happening Behind The Panels
Once we arrive, we’ll test safeties and components you shouldn’t access on your own. Common culprits include:
- Igniter failure: Silicon carbide or nitride igniters can crack with age and cycling.
- Flame sensing issues: A flame sensor dirty with oxidation can stop the control from proving flame.
- Pressure switch or inducer problems: If exhaust can’t move, ignition won’t start.
- Blocked intake or exhaust: Wind-blown debris or ice near the vent terminations.
- Gas supply interruptions: Neighborhood work or a closed valve upstream.
- Control board logic faults: Intermittent relays or failed solder joints.
- High-limit trips: Restricted airflow or undersized returns causing overheating.
Each issue has a different fix. That’s why we start with a full diagnostic. We verify safe operation, confirm parts, and test the system after service so you know the heat is steady.
Local Factors That Affect Ignition In Pittsburgh
Our hills and valleys create microclimates. A home in Mt. Washington can face biting wind, while a brick rowhome in Lawrenceville may trap damp air in the basement. Both can influence venting, draft, and how reliably burners light. Homes with older chimneys in Bloomfield or Polish Hill sometimes need liner evaluation when systems are upgraded, and sidewall-vented units in Moon Township or Bethel Park may need careful placement to avoid snow drifts.
If your furnace won’t ignite after a wet snow or sudden freeze, tell us about any weather you observed. These clues often lead us to the solution faster.
When To Stop Troubleshooting And Call A Pro
It’s normal to feel tempted to keep tinkering. But there are clear signs to pause and reach out:
- You notice a persistent gas smell or a hissing sound.
- The status light shows a repeated error after brief operation.
- You see water around a high-efficiency furnace or hear a pump running nonstop.
- The thermostat is unresponsive even after replacing its batteries.
- Heat returns briefly, then the furnace shuts down again.
Protect your family with working carbon monoxide detectors. If any alarm sounds, go outside and call emergency services.
How Mitchell Plumbing, Heating and Cooling Gets Your Heat Back
When you contact our team, we start by reviewing your notes and any photos of error codes. A trained technician checks safeties, verifies ignition sequence, and tests airflow and venting. If parts are needed, we match specifications to your system so the repair lasts. We serve homeowners across the city and nearby suburbs, from Cranberry Township to Monroeville, with careful, respectful service in every home.
If your system has already tried and failed multiple starts, it may be in a timed lockout. We’ll clear that safely, address the root cause, and confirm steady operation through several cycles. If you’re planning ahead, we can also discuss upkeep to reduce nuisance shutdowns without making any hard sell.
Ready to bring the warmth back? You can schedule furnace service and talk to a person who understands Pittsburgh homes. Or speak with us now at 888-996-4824.
Staying Comfortable The Smart Way
Simple routines help avoid surprise lockouts. Keep an eye on filter change intervals that match your home and pets. After major storms, glance at the outdoor vent area from a safe distance. And if your thermostat has a schedule, pick one that fits your family’s winter routine so the furnace isn’t asked to recover from big temperature setbacks during the coldest hours.
When you need fast, local help, bookmark this page and save our number. You can also find help when your furnace won’t ignite right from our home page when the next cold front rolls in.
Ready For Warmth? We’re Here To Help
Whether you’re in a brick classic in Bloomfield or a newer build in Robinson Township, Mitchell Plumbing, Heating and Cooling is ready to help. Call 888-996-4824 and we’ll get you on the schedule. If you want a quick overview of what we do and how we can help today, visit our furnace services page and let us know what you’re experiencing in your Pittsburgh-area home.
If your furnace won’t ignite, you’re not alone. We restore heat safely and treat your home with care.
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