Wirtz, VA Heating System Repair: 5 Common Failures

Estimated Read Time: 10 minutes

If your heater not working has you bundling up, you are not alone. Cold snaps hit the Roanoke Valley hard, and small issues can shut down heat fast. In this guide, you will learn the top five causes and simple checks you can do safely. When a fix needs a pro, we explain the why and the next step. Free estimates are available if you need repair or replacement.

Safety First: Quick Checks Before You Troubleshoot

If a heater stops, start with safe basics. These quick steps often reveal a simple issue and help you describe symptoms if you call for service.

1. Confirm power and fuel:
   • Electric systems: Test another device on the same outlet or circuit.
   • Gas systems: Make sure the gas valve is open. If you smell gas, leave and call your utility and a pro.
2. Thermostat basics:
   • Heat mode on, temperature set above room temp by 3 to 5 degrees.
   • Replace batteries if the display is dim or blank.
3. System status:
   • Look for error lights on furnaces and heat pumps.
   • Listen for the blower, outdoor unit, or ignition attempts.
4. Airflow and venting:
   • Replace a clogged filter.
   • Make sure supply and return vents are open and not blocked by rugs or furniture.

If these do not restore heat, move through the five most common causes below.

1) Thermostat Settings or Power Problems

A surprising number of heater not working calls come down to the thermostat. If it is not sending a call for heat, the system will not start.

What to check:

• Mode: Set to Heat, not Cool or Auto. Some Auto modes delay heat.
• Temperature: Set a few degrees above current room temp.
• Schedule: Temporarily disable schedules to rule out setbacks.
• Fan setting: Auto is usually best for heating.
• Batteries: Replace AAA or AA batteries if used.
• Location issues: Direct sunlight or a draft can cause false readings. If a door or window draft hits the thermostat, it may think the home is warmer or colder than it is.

When to call a pro:

• Blank screen even after new batteries.
• Old mercury or incompatible smart thermostats after a new system install.
• Loose low‑voltage wiring, shorted wires, or failed control boards.

Pro tip:

• If you recently upgraded Wi‑Fi thermostats, confirm your system type in the app setup. Heat pump systems with auxiliary heat require the correct configuration for strip heat or furnace backup.

2) Tripped Breaker or Blown Fuse

Electric furnaces, heat pumps, and blower motors rely on dedicated circuits. A surge, short, or motor overload can trip protection.

What to check:

• Breaker panel: Look for a breaker in the middle position. Turn it fully off, then back on.
• Outside disconnect: Heat pumps and some furnaces have an outdoor shutoff. Ensure it is on.
• Service switch: Many air handlers have a wall switch that looks like a light switch. Make sure it is on.
• GFCI outlets: In finished basements or garages, a tripped GFCI can cut control power.

If the breaker trips again immediately, stop and call. Repeat tripping suggests an electrical fault or motor issue that needs testing with proper tools.

When to call a pro:

• Repeated trips, warm wiring smell, or humming motors that do not start.
• Visible damage to wiring, contactors, or capacitors.

Pro tip:

• Label the HVAC breakers now. Clear labeling speeds safe diagnostics during an emergency and helps you describe what tripped when you call.

3) Dirty Filter or Blocked Airflow

Airflow is the lifeblood of a heating system. A clogged filter or blocked return causes overheating and short cycling for gas furnaces, and poor heat output for heat pumps.

What to check:

• Filter condition: If you cannot see light through the filter, replace it.
• Filter size and MERV: A too‑thick or high‑MERV filter can starve airflow if your blower is not sized for it.
• Vents and returns: Open all supply registers and clear the return grille. Do not close more than 10 percent of vents.
• Coils: Heat pumps use indoor coils. A dirty coil reduces heat transfer and comfort.

DIY fix:

1. Replace the filter with the correct size and air rating.
2. Vacuum dust at the return grille and around the furnace cabinet.
3. Allow the system to run 15 to 20 minutes and recheck temperature rise.

When to call a pro:

• Repeated flame rollout or limit switch trips on a gas furnace.
• Ice on the heat pump’s outdoor unit in mild weather.
• Musty odors that suggest coil contamination.

Pro tip:

• Mark a filter change date on your phone every 60 to 90 days. Homes near the Roanoke River greenway or on gravel roads often need more frequent changes due to dust and pollen.

4) Ignition, Pilot, or Gas Supply Issues (Furnaces and Boilers)

If your gas furnace clicks but does not light, the issue is often in the ignition sequence. Modern systems use hot surface igniters or spark ignition. Older units may have standing pilots.

What to check safely:

• Thermostat calls for heat and the indoor blower starts.
• Furnace door switch is engaged. A loose panel stops ignition.
• Watch through the sight glass for a glow from the igniter. If you do not see glow or spark, the igniter may be open.
• For standing pilot systems only: If the pilot is out, follow the manufacturer label on the unit to relight. If it will not stay lit, the thermocouple may be failing.

When to call a pro immediately:

• You smell gas. Leave the home and call your utility and a licensed technician.
• The furnace locks out after multiple tries.
• Soot, scorch marks, or burnt wiring in the burner area.

Why a pro is important here:

• Gas pressure, flame sensor microamps, and combustion analysis require tools and training. A pro will also inspect venting and heat exchanger integrity to protect against carbon monoxide.

Pro tip:

• If your furnace is over 15 years old and repairs involve a cracked heat exchanger or repeated ignition failures, discuss replacement options. Free estimates are available, and financing through GoodLeap can reduce upfront cost.

5) Heat Pump Not Heating Enough or Stuck in Defrost

In our region, many homes use heat pumps. When temperatures drop, they rely on auxiliary electric heat. Problems with refrigerant charge, outdoor fan motors, or control boards can leave a heat pump blowing cool air.

What to check:

• Mode: Confirm Heat, not Emergency Heat unless directed by a tech.
• Defrost cycle: Light steam on the outdoor unit for a few minutes can be normal. Heavy ice that persists is not.
• Airflow: Dirty filters and coils reduce heat transfer in winter.
• Thermostat balance point: Some controls lock out the heat pump below a set temperature.

When to call a pro:

• Outdoor unit iced over solid.
• Breakers trip when strips engage.
• Short cycling or loud compressor starts.
• Suspected low refrigerant. Refrigerant handling requires EPA certification.

Pro tip:

• A generator can keep heat pumps and air handlers running during outages. Bob Garrett Services is the largest residential generator dealer in Southwest Virginia, and whole home backup can protect HVAC, medical devices, and sump pumps during winter storms.

When Repair Makes Sense vs. Replacement

Use the 50 percent rule as a guide. If the repair cost is over half the value of a new system and your unit is near the end of its typical life, consider replacement.

Typical lifespans:

• Gas furnace: 15 to 20 years with maintenance.
• Heat pump: 10 to 15 years, depending on usage and maintenance.
• Boilers: 20 years or more with proper care.

Reasons to repair:

• Minor parts like igniters, flame sensors, capacitors, or contactors.
• Young equipment under warranty.

Reasons to replace:

• Cracked heat exchanger, failed compressor, or repeated control board failures.
• Poor comfort, rising energy bills, and frequent breakdowns.

Financing and incentives:

• We offer flexible payment options through GoodLeap to help spread costs.
• Ask about utility rebates or manufacturer promos on qualifying high‑efficiency systems.

Preventative Maintenance That Prevents No‑Heat Emergencies

An annual tune‑up pays for itself in fewer breakdowns and safer operation.

What a pro maintenance visit includes in principle:

1. Safety checks: Gas pressure, combustion, venting, and carbon monoxide review.
2. Electrical tests: Capacitors, contactors, amp draws, and thermostat calibration.
3. Airflow health: Filter, blower wheel, and coil inspection with static pressure checks.
4. Heat pump care: Defrost function, refrigerant temps and pressures, and outdoor coil cleaning.

Homeowner habits that help:

• Change filters every 60 to 90 days or more in dusty homes.
• Keep 2 feet of clearance around outdoor units.
• Do not block returns with furniture.
• Note unusual noises or smells early and call before a failure.

Value to you:

• Better comfort, lower bills, and longer equipment life. Many no‑heat calls we see start with clogged filters or neglected coils.

What To Tell Your Technician When You Call

Accurate details help us fix your heater faster.

Share these:

• Equipment type and age if known.
• What you hear or see when it tries to start.
• Any smells, error codes, or flashing lights.
• What you already tried, including breaker resets and filter changes.
• Recent work done on the system or electrical panel.

This information speeds diagnosis and can reduce trip time.

Why Homeowners in the Roanoke and New River Valleys Choose Us

• Local expertise: We service homes from Salem to Christiansburg and know how winter winds on Bent Mountain expose weak systems.
• Dedicated HVAC team: Our roster includes roles like HVAC and Plumbing Operations Manager and HVAC Comfort Advisor.
• Proven service: Reviews cite professional installs, prompt response, and clean work.
• Options that fit your budget: Free estimates and GoodLeap financing for approved customers.
• Whole home reliability: Generator solutions available so heat stays on during outages.

DIY Fixes You Can Try Right Now

• Replace the filter and open all vents.
• Set the thermostat to Heat, fan to Auto, and change batteries.
• Check the breaker and HVAC service switch.
• Reset a tripped outdoor GFCI if your air handler is on that circuit.
• Clear snow and leaves from around the outdoor unit.

If the heater not working issue continues after these steps, call for same‑day diagnostic service. Fast action can prevent bigger repairs.

Special Offer: Free Estimate on Heating Repair or Replacement

Get a no‑cost estimate on furnace or heat pump repair and on new system installs. Call 540-583-4765 or visit https://bobgarrettservices.com/ to schedule. Offer available through Feb 4, 2026. Financing available through GoodLeap for qualified projects.

What Homeowners Are Saying

"Had our furnace replaced this week. The team was professional, courteous and even left the place cleaner than when they arrived. I would highly recommend them..."
–Jaime M., Furnace Replacement

"always very helpful and prompt when needed! our furnace install went perfectly and our heat is working again!"
–Courtney F., Furnace Install

"Shaun and David came out to inspect our HVAC and furnace when it wasn't keeping up with the thermostat. They came out right away and took care of the issue."
–Todd S., HVAC Diagnostic

"David, Peyton and Trenton did a great job installing the correct Furnace. They all were polite and respectful! They even cleaned up everything!"
–Tina Q., Furnace Install

Frequently Asked Questions

Why is my heater running but not warming the house?

Common causes include clogged filters, low airflow, heat pump defrost issues, or incorrect thermostat settings. Try a new filter and confirm Heat mode. If airflow is good and temps stay low, schedule a diagnostic.

Is it safe to relight my furnace pilot light?

Only if your unit has a standing pilot and the manufacturer’s instructions are present. If the pilot will not stay lit or you smell gas, stop and call a professional immediately.

How often should I change my furnace filter in winter?

Most homes do well with 60 to 90 days. Homes with pets, renovations, or heavy dust may need monthly changes. Always use the correct size and rating.

What does it mean if my heat pump ices over?

Light steam during a brief defrost is normal. A block of ice or repeated icing points to airflow or refrigerant issues. Turn the system off and call for service to prevent damage.

When should I repair vs. replace my heater?

If the repair is over 50 percent of the cost of a new unit and your system is nearing the end of its life, replacement is smart. Ask for a free estimate and financing options.

Bottom Line

A heater not working usually traces back to thermostat settings, power issues, airflow, ignition, or heat pump performance. Start with safe checks. If the problem persists, our licensed team will get heat back fast across the Roanoke and New River Valleys. Free estimates and financing are available.

Ready for Warmth Today?

Call 540-583-4765 or visit https://bobgarrettservices.com/ to schedule. Ask for your free estimate by Feb 4, 2026.

Call now: 540-583-4765 Schedule online: https://bobgarrettservices.com/ Active offer: Free estimate on heating repair or replacement through Feb 4, 2026. Financing available via GoodLeap for qualified projects.

About Bob Garrett Services

Bob Garrett Services is a trusted local team serving the Roanoke and New River Valleys with HVAC, plumbing, and electrical expertise. Homeowners choose us for certified technicians, clean installs, and responsive service. We offer free estimates and flexible financing through GoodLeap. Our team includes dedicated HVAC specialists and we are recognized as the largest residential generator dealer in Southwest Virginia. Your comfort and safety are our priority, every visit.