Heating Troubleshooting
Furnace Not Turning On in Brooklyn — What to Check
A gas furnace that won't fire up has a short list of causes. In Brooklyn most no-heat calls trace to one of five parts. Here's how to narrow it down — safely — before paying for a service call.
Anatomy of the system
Numbered parts below match the cost table further down — so you can see exactly where the failure usually sits.
- 1Hot surface ignitor — cracks and burns out (5–7 yr life)
- 2Flame sensor — sooted up, won't prove flame
- 3Gas valve — failed coil or stuck closed
- 4Control board — relays / thermostat circuit
- 5Inducer / pressure switch — won't prove draft
Step-by-step troubleshooting
Run through these in order. The DIY checks are safe; the red callouts mean stop and call us.
- 1
Confirm thermostat, power, and gas
Sounds basic, but it's the #1 cause of unnecessary service calls. Confirm three things before assuming a furnace failure.
Try this before calling
- Thermostat set to HEAT, temperature set 5°F above room temp, fresh batteries
- Furnace switch (looks like a light switch on the side of the unit) is ON
- Gas is on at the meter and other gas appliances (stove) work
Still not working? Call (347) 997-3360 — diagnostic visits are flat-rate and credited toward the repair.
- 2
Watch one full ignition attempt
Stand near the furnace and listen. A normal sequence: thermostat calls heat → inducer fan whirs (30s) → click → ignitor glows → gas valve opens → burners light → blower starts (60s later). If it stops at any step, that's where the failure is.
Try this before calling
- If you hear the inducer but no click — control board or pressure switch
- If you hear ignitor & click but no flame — gas valve or no gas
- If burners light then shut off after 5 seconds — dirty flame sensor (cheapest fix)
Still not working? Call (347) 997-3360 — diagnostic visits are flat-rate and credited toward the repair.
- 3
Check / replace the air filter
A clogged filter trips the high-limit safety switch — the furnace will start, run a few minutes, then shut off and lock out. If the cabinet feels hot to the touch and the system locks out, that's the symptom.
- 4
Smell gas? Stop everything.
Any smell of gas — even faint — means stop and call.
Gas smell = evacuate, do not start the furnace
If you smell gas: leave the building, don't flip switches, call 911 or National Grid (1-718-643-4050) from outside, then call us. Never restart a furnace after a gas event without a tech inspecting it.
What this usually costs in Brooklyn
Real-world ranges for Brooklyn homes. The exact number depends on parts, access, and how long it's been failing.
| Issue | Likely cause | Typical range |
|---|---|---|
| Clean flame sensor | Sooted sensor not proving flame | $245 – $385 |
| Replace hot surface ignitor | Ignitor cracked / burned out | $385 – $625 |
| Replace flame sensor | Sensor degraded beyond cleaning | $385 – $585 |
| Replace pressure switch | Switch won't prove draft | $425 – $725 |
| Replace inducer motor | Inducer fan failed | $725 – $1,250 |
| Replace gas valve | Valve stuck or coil failed | $650 – $950 |
| Replace control board | Board fault, no sequence | $725 – $1,450 |
Clean flame sensor
Sooted sensor not proving flame
$245 – $385
Replace hot surface ignitor
Ignitor cracked / burned out
$385 – $625
Replace flame sensor
Sensor degraded beyond cleaning
$385 – $585
Replace pressure switch
Switch won't prove draft
$425 – $725
Replace inducer motor
Inducer fan failed
$725 – $1,250
Replace gas valve
Valve stuck or coil failed
$650 – $950
Replace control board
Board fault, no sequence
$725 – $1,450
Typical range. Final cost confirmed on site after diagnosis.
Common Questions
Related Brooklyn HVAC services
Need a Brooklyn tech today?
Same-day diagnostics when we can fit you in. Flat-rate visit, credited toward the repair.
(347) 997-3360