It’s 2am in January. The temperature outside is 15°F. You wake up cold and realize your furnace isn’t running. In Denver, this isn’t just uncomfortable — it can become dangerous within hours for elderly family members, young children, pets, and your home’s plumbing. Here’s exactly what to do.
Step 1 — Check the Obvious First (Solves ~30% of Emergency Calls)
☐ Thermostat: Is it set to “Heat”? Is the set temperature above room temperature? Are batteries dead?
☐ Furnace power switch: The ON/OFF switch near the furnace (looks like a light switch) — make sure it’s ON
☐ Circuit breaker: Look for a tripped breaker labeled “HVAC,” “Furnace,” or “Heat” and reset it
☐ Furnace filter: A severely clogged filter causes overheating and auto-shutdown — replace if visibly dirty
☐ Gas supply: Check other gas appliances (stove, water heater) — if none work, the issue is your gas service
☐ Furnace door: Most furnaces won’t run if the access panel isn’t fully closed
Step 2 — Try the Reset Button
Most furnaces have a small red or yellow reset button on the burner assembly. Press it once. If the furnace starts and runs normally, monitor it. If it shuts down again, do not press reset repeatedly — this signals a deeper problem requiring a technician.
Step 3 — Keep Your Home Safe While You Wait
- Close off unused rooms to concentrate warmth in a smaller space
- Use electric space heaters safely — 3 feet from flammables, never leave unattended
- Let faucets drip slightly if temperatures are very low to prevent pipe freezing
- Never use gas ovens, outdoor grills, or generators indoors — carbon monoxide risk
Step 4 — Call for Emergency Furnace Repair
Tell the technician: furnace make, model, and age · what it’s doing (not starting, starts then shuts off, making noise) · what you’ve already tried · your address. Aether Mechanical provides emergency furnace repair in Denver and the surrounding metro area. Call anytime: (303) 414-7770.
Common Causes of Nighttime Furnace Failures
- Dirty flame sensor — most common cause of “starts then immediately shuts off”
- Failed ignitor — furnace tries to start but nothing happens
- Tripped high-limit switch — caused by overheating, often from a clogged filter
- Gas valve issue — no fuel reaches the burner
- Control board failure — furnace can’t sequence startup properly
Frequently Asked Questions
Q: Is a broken furnace in Denver a real emergency?
Yes, in winter. Denver temperatures regularly drop below 15°F at night. A home without heat can reach dangerous temperatures within hours, and pipes can freeze and burst below 20°F.
Q: What should I do if my furnace makes a loud bang when starting?
A loud bang usually signals delayed ignition — gas building up and igniting all at once. Stop using the furnace and call a technician — it can damage the heat exchanger over time.
Q: How much does emergency furnace repair cost in Denver?
Emergency repairs typically cost $150–$300 more than standard rates due to after-hours labor. Aether Mechanical provides upfront pricing — no surprises. Call (303) 414-7770.
Q: How can I prevent this from happening again?
Annual furnace maintenance in September or October is the most effective prevention. A professional tune-up catches dirty sensors, aging ignitors, and clogged filters before they cause a wintertime breakdown.
Need emergency furnace repair in Denver right now? Aether Mechanical is available 24/7 throughout the metro area.
