Furnace Not Heating — Troubleshooting

Why Is My Furnace Running But Not Heating?

Most common causes: dirty filter, pilot/ignitor failure, gas valve closed, flame sensor dirty, thermocouple bad, or blower motor failing. Below: what to check yourself before calling our heating team.

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Signs You Need Service

6 Reasons Your Furnace Isn’t Heating

Ranked by frequency on actual NJ winter service calls.

Dirty Air Filter

Check first. Clogged filter restricts airflow, can trigger high-limit safety shutoff. Look at your filter — opaque = swap it. Reset furnace power, give 5 min, restart. If issue returns, deeper problem.

Thermostat Issue

DIY checks: Is it set to HEAT mode (not OFF or COOL)? Setpoint above current temp? Battery dead (on battery-powered models)? Replace batteries before calling us — saves you $197.

Pilot Light / Ignitor Failure

Older furnaces: standing pilot light out — relight per furnace manual. If it won’t stay lit, thermocouple failure ($150-$300 part). Newer furnaces: electronic hot-surface ignitor cracks/burns out — $250-$450 to replace. Call us for either.

Gas Valve Off or Tank Empty

Natural gas: check the gas valve at the furnace — should be parallel to the pipe (open). Propane: check tank level — we’ve had multiple winter calls where the tank ran dry. Easy fix, no charge if that’s it.

Dirty Flame Sensor

Flame sensor tells the gas valve flame is present. Soot buildup = false “no flame” reading = gas shuts off. Symptom: furnace fires for 5-10 sec, then shuts off, retries. We clean for $150-$250 — sometimes part of tune-up.

Blower Motor or Capacitor

Furnace fires but no air through vents = blower issue. Could be capacitor ($300-$500), motor ($500-$900), or control board ($400-$700). Diagnostic needed — we’ll inspect and give you the actual number.

Simple, Upfront Pricing

Know What You’ll Pay. Every Time.

Clear options, clear written options. Every quote includes parts, labor, and our written support.

A/C Maintenance

$188
Preventive maintenance visit
  • Multi-point AC inspection
  • Clean condenser coils
  • Check refrigerant levels
  • Test thermostat & controls
  • Priority scheduling included

Schedule Tune-Up

New Install / Replacement

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Custom estimate, no obligation
  • In-home sizing assessment
  • Multiple system options quoted
  • Financing & rebate guidance
  • available manufacturer warranty options
  • Same-team removal & install

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Our Process

How a Service Call Actually Goes

No mystery fees, no pressure, no sales pitch. Here’s exactly what happens from your first call to the last handshake.

01

Schedule

Book online or call (908) 284-2422. We call back within 30 minutes during business hours.

02

Diagnose

A factory-trained tech arrives on time, identifies the issue, and walks you through exactly what we found.

03

Upfront Quote

You get a written quote before any work begins. Approve it or walk away — no pressure, clear written options.

04

Repair & Support

We fix it — often quick — and back every repair with a 2-year parts & labor warranty.

Reviews

What Our Customers Say

4.9750+ Google reviews
Ken C.
Flemington, NJ

★★★★★

After our second-floor AC went out, Kayla called before 8 the next morning and Hilmi had us back in business by 9:30.

3 weeks ago
Edward D.
Bridgewater, NJ

★★★★★

Outstanding professional service. The team went above and beyond to fix the problem while communicating throughout.

1 month ago
Daniela D.
Hillsborough, NJ

★★★★★

Very professional, reliable, and knowledgeable. I would highly recommend them to friends and neighbors.

2 months ago
Is it safe to keep running my furnace if it’s not heating?
Stop and call us if you see/smell: gas odor (call gas utility FIRST: PSE&G 1-800-880-PSEG / Elizabethtown Gas 1-800-242-5830), soot around the furnace, yellow flames (should be blue), strong burnt-electrical smell. These are CO/fire risks.
Why does my furnace keep turning on and off (short cycling)?
See our short-cycling guide — usually overheating from a dirty filter, oversized furnace, or bad flame sensor.
How much does furnace repair cost?
Typical range: $200-$1,200. Flame sensor cleaning: $150-$250. Thermocouple: $200-$400. Hot-surface ignitor: $300-$500. Blower motor: $500-$900. Gas valve: $500-$900. See our cost guide.
Should I have a CO detector if I have a gas furnace?
Yes, absolutely. NJ code requires CO detectors near sleeping areas. We install them during tune-ups if missing — $40-$80 hardwired.
How fast can you get to a no-heat call in winter?
Cold homes get priority — we usually dispatch quick during heating season, even on weekends. Call us — we’ll be honest about ETA.
My furnace is 18 years old — repair or replace?
Lean replace. 18-year-old furnaces are at end of life. New high-efficiency furnace (95% AFUE) cuts gas bills 15-25% and qualifies for federal/state rebates. See repair vs replace framework.
Ready When You Are

Furnace Down? Quick Heating Service.

Cold homes get priority dispatch. $197 diagnostic, waived with repair. our satisfaction guarantee support on every repair.