jeffbonar 
If your home is chilly and the furnace isn’t keeping up, try these quick, safe checks. We understand that being left with no heat can be scary, but help is always nearby from the pros at Ross & Witmer. Most of these steps take under a minute and can save you a service call. If anything smells like gas, you hear alarming noises, or a CO alarm sounds—leave the home and call a professional immediately for heating repair.
Before you start: safety first
- If you smell gas or your CO alarm is beeping, exit the home and call a pro/utility.
- Don’t remove burner doors, reach into moving parts, or bypass any safety switches.
- If you’re uncomfortable at any step, stop and call Ross & Witmer.
1) Thermostat sanity check
- Heat mode on? Setpoint at least 3–5°F above room temp.
- Fan set to AUTO (not ON) to avoid continuous “fan-only” cold air.
- Replace batteries if the display is dim/blank. If it has Wi-Fi, confirm it’s online.
2) Power and breakers
- Verify the furnace switch (looks like a light switch near the unit) is ON.
- Check the breaker labeled furnace/air handler and the outside unit breaker (for heat pumps). Reset once if tripped.
3) Air filter & returns
- A clogged filter can trigger safety limits and blow cool air. Replace if dirty.
- Make sure return grilles aren’t blocked by furniture, rugs, or holiday décor.
4) Vents & dampers
- Open supply vents at least 80% in lived-in rooms.
- If you have manual dampers on ductwork, set them to open for heating.
5) Condensate overflow switch
- High-efficiency furnaces and many air handlers have a float switch that shuts the system off if the drain pan fills.
- Look for water in the pan; if full, gently remove power and call for service—don’t defeat the switch.
6) Gas furnace: call-worthy quick checks
- Gas valve to the furnace should be parallel (open). If unsure, do not force it.
- If you have an older standing pilot and it’s out, don’t relight unless you’re fully comfortable—call a pro.
- Frequent starts/stops (“short cycling”) often means a safety trip—time to call us.
7) Heat pump users: know defrost vs. no heat
- On cold, damp days, your outdoor unit may steam and pause briefly—this is normal defrost, not a failure.
- If the outdoor fan never spins, you see thick ice buildup, or breakers keep tripping—that’s not normal.
8) Emergency Heat (AUX)
- Use Emergency Heat only if the heat pump won’t run; it’s expensive backup heat.
- If indoor air feels warm only in Emergency Heat, your heat pump likely needs service.
9) Odors & noises
- Burnt dust for a few minutes at first start-up can be normal.
- Sharp electrical smell, metallic scraping, or booming sounds are not—shut it down and call.
10) When DIY ends
- If you’ve tried the steps above and you’re still cold, or the system trips again later, book a professional diagnosis.
- Ask about a maintenance plan to prevent surprise breakdowns in peak season.
Service area
We repair and maintain furnaces and heat pumps across Charlotte, Gastonia, Huntersville, Matthews, Mint Hill, and nearby communities.
Clear next steps
- Need same-day heat? Contact Ross & Witmer for prompt, professional heating repair.
- Considering replacement? We’ll price out repair vs. replacement so you can decide confidently.
FAQs
Q1: Why is my furnace blowing cold air?
Fan set to ON, clogged filters causing a safety limit trip, or ignition issues are common causes. Set fan to AUTO, replace the filter, and if it persists, call a pro.
Q2: My heat pump is steaming—do I have a problem?
Probably not. In cold, humid weather, heat pumps run a defrost cycle that looks like steam. If the outdoor fan never runs or the unit is encased in ice, call for service.
Q3: When should I use Emergency Heat?
Only when the heat pump can’t run. It uses electric resistance heat that’s far more expensive than normal operation.
Q4: How often should I change the furnace filter in winter?
Check monthly; replace every 1–3 months depending on filter type, pets, and dust.
Q5: When is repair vs. replacement smarter?
If the unit is 15+ years old, has a cracked heat exchanger, or faces a repair near 30–40% of the cost of a new system, ask for replacement options.
