Elliston, VA Heat Pump Not Blowing Hot Air? HVAC Fixes

Estimated Read Time: 12 minutes

A heat pump not blowing hot air can turn a chilly Blue Ridge morning into a scramble. Before you panic, use this quick guide to rule out simple issues and restore comfort fast. If you prefer a pro, our NATE-certified team in the Roanoke Valley can test, diagnose, and fix today. Keep reading for DIY steps, safety tips, and the exact moments to call for help.

Start Here: Quick, Safe Checks

Small settings and power issues cause many no-heat calls. Run these checks first:

1. Confirm the thermostat
2. • Set to Heat, not Cool.
   • Fan on Auto, not On. On runs the blower without heat.
   • Raise the setpoint at least 3 degrees above room temperature.
2. Check breakers and switches
3. • Main panel: reset tripped HVAC and air handler breakers.
   • Outdoor unit: verify the service disconnect is inserted and on.
3. Look at system status
4. • Many thermostats show Heat On, Aux Heat, or Defrost. Note what you see.
4. Wait one full cycle
5. • Heat pumps need a few minutes to ramp up and move warm air.

If supply air feels slightly warmer than room temperature but not hot, your system may be working but underperforming. Continue below.

Understand What “Warm” Feels Like From a Heat Pump

Unlike a gas furnace, a heat pump delivers a steady stream of warm air that may feel mild. Typical supply air from a healthy heat pump can be 85 to 95°F. In a 70°F room, that feels warm at the register, not hot. When outdoor temperatures drop, the unit may use auxiliary heat to keep up.

Signs of normal operation:

• Air is warmer than room temperature.
• Outdoor fan runs, pauses for defrost, then resumes.
• Thermostat occasionally shows Aux Heat on cold days.

Signs of a problem:

• Air feels room temperature or cooler for several cycles.
• Outdoor unit ices over and stays iced for more than 60 minutes.
• Breakers trip again after a reset.

Thermostat Misconfigurations That Kill Heat

A wrong thermostat mode or schedule can stop heat.

Try this:

1. Turn off any programmed schedule temporarily.
2. Set Heat mode with a simple Hold at your desired temperature.
3. If you have a heat pump specific thermostat, confirm the equipment type is set to Heat Pump with Auxiliary Heat, not Gas or Conventional.
4. Replace batteries if your thermostat uses them.

When to call:

• If the thermostat will not call for heat at all.
• If the display is blank even after new batteries and breaker checks.

Airflow First: Filters, Vents, and Return Issues

Low airflow prevents the indoor coil from absorbing heat. Start here before you suspect parts.

• Filter: Replace a clogged filter. If you cannot see light through it, it is overdue. Use the correct size and orientation.
• Returns: Keep return grilles open and clear. Do not block with furniture.
• Supply vents: Open every vent at least half way. Close too many and static pressure spikes.
• Indoor coil: If you can see the coil and it is packed with dust, schedule a professional cleaning. Coils should be cleaned with proper chemicals and rinse methods.

Clues you have an airflow problem:

• Whistling at returns.
• Weak airflow at multiple rooms.
• Coil frosting on the indoor unit.

Outdoor Unit in Winter: Frost vs. Freeze-Up

Heat pumps pull heat from outdoor air. In cold and damp weather, the outdoor coil will frost. That is normal. The unit will enter a defrost cycle for several minutes, melt the frost, then return to heat.

Normal defrost signs:

• You hear a change in tone and a pause in outdoor fan operation.
• Steam rises off the coil for a short time.
• After a few minutes, the unit resumes heating.

Not normal:

• Solid ice encasing the entire outdoor unit for an hour or more.
• Fan blade stuck in ice.
• Repeated trips to defrost with little heat inside.

What you can do:

1. Shut power off at the disconnect if the fan is stuck in ice.
2. Gently clear snow from around the base. Keep 18 inches of clearance.
3. Do not chip ice off the coil. Call a pro to prevent coil damage.

Electrical and Backup Heat Checks

Most air handlers include electric heat strips for auxiliary or emergency heat. If strips fail, air may feel cooler on very cold days.

• Breakers: Some systems have a separate breaker for heat strips. Check the panel for two HVAC breakers.
• Thermostat test: Switch to Emergency Heat for a few minutes. If air becomes hot, the outdoor unit may be the issue. If it remains cool, the backup heat may be offline.
• Burning smell: A slight dusty odor is normal the first time strips heat in a season. A sharp, ongoing burning smell is not. Turn off and call.

Refrigerant Problems: Symptoms You Can Detect

You cannot test refrigerant without gauges, but your senses can spot symptoms.

• Long run times with little temperature rise.
• Outdoor unit and lines appear frosty in mild weather.
• Hissing or bubbling at the indoor unit.

Low refrigerant often points to a leak. Adding refrigerant without repair is a short-term patch and can be illegal if the leak is not addressed. A licensed technician should locate and repair the leak, then weigh in the factory charge.

Defrost and Reversing Valve Issues

Two common faults can stop heat entirely.

• Stuck reversing valve: The system may cool when set to Heat. Air feels cold, not mild.
• Defrost board failure: The outdoor coil ices over and never clears. Heat output collapses.

Both faults require tools and testing. If you see these signs, skip further DIY and schedule service.

Ductwork and Zoning Problems

Leaky or disconnected ducts steal heat. In older Roanoke homes and crawlspaces around Rocky Mount and Wirtz, we often find fallen flex ducts and crushed runs.

Check what you can see safely:

• Look for separated joints near the air handler.
• Feel for strong airflow in some rooms and weak or cold air in others.
• Listen for rattles or flapping noises that rise with fan speed.

Sealing and balancing ducts restores comfort and helps your heat pump meet its rated efficiency.

When Outdoor Temperatures Drop Below the Balance Point

Every home has a balance point where the heat pump needs help from auxiliary heat. On many systems, this is near the mid 30s°F, depending on home insulation and system size.

What to expect:

• Longer heat pump run times.
• Periodic Aux Heat operation to maintain setpoint.
• Supply air that is warm, not hot, while the heat pump runs.

If it never reaches setpoint or rooms cool off while the system runs constantly, you likely have a performance fault. Move to the pro checklist below.

Pro-Level Checklist: What Our Techs Test On Arrival

When you call, our NATE-certified technicians arrive in a fully stocked vehicle and follow a proven diagnostic path.

1. Electrical safety and code compliance
2. • Tighten high-voltage and low-voltage connections.
   • Verify proper breaker sizing and wire condition.
2. Airflow and static pressure
3. • Measure filter, coil, and duct drops with a manometer.
   • Confirm blower speed settings and tap selection.
3. Refrigerant circuit
4. • Record suction and liquid pressures, superheat, and subcooling.
   • Compare to manufacturer charts for the exact outdoor temperature.
4. Defrost and controls
5. • Test sensors, defrost board timing, and reversing valve operation.
   • Confirm thermostat programming and equipment configuration.
5. Heat strip function
6. • Amp draw test vs. nameplate rating.
   • Stage sequencing to avoid light-dimming and short cycling.

You receive a written report card of pressures, cleaning performed, adjustments made, and any recommendations. This is part of our Without Worry Comfort Check process. It is a clear record you can keep for warranties and resale.

Maintenance That Prevents No-Heat Calls

Heat pumps love clean coils, correct charge, and proper airflow. Simple routines pay off every season.

Seasonal tasks for homeowners:

• Replace filters every 1 to 3 months.
• Keep 18 inches of clearance around the outdoor unit.
• Rinse debris from the outdoor coil with low-pressure water.
• Confirm condensate drains freely.
• Gently vacuum return grilles.

Professional tune-up tasks we perform:

• Deep clean outdoor and indoor coils as needed.
• Test capacitors, contactors, relays, and sensors.
• Calibrate thermostat and verify staging.
• Measure static pressure and balance airflow.
• Verify defrost operation and heat strip stages.

Our team documents all findings so you know what we did and why. Members of our Diamond Club receive up to three complimentary Without Worry Comfort Checks annually, a reduced $69 service fee, and 10% off HVAC and plumbing repairs for only $24 per month.

Two Hard Facts You Can Count On

• Local track record: Wisler has served Roanoke area homeowners since 1986 and is recognized by the Better Business Bureau for Home Services in Virginia.
• Technician standards: Our team includes NATE-certified technicians who use advanced diagnostic tools to catch issues early and document precise pressures and adjustments in a written report.

DIY Troubleshooting Flow

Follow this order to save time and avoid damage:

1. Thermostat and mode
2. • Heat, not Cool. Fan on Auto. Raise setpoint 3 degrees.
2. Power path
3. • Check both indoor and outdoor breakers. Confirm outdoor disconnect is on.
3. Airflow
4. • Replace filter. Open vents. Inspect visible ducts.
4. Outdoor unit
5. • Clear snow. Watch for normal defrost. Do not chip ice.
5. Backup heat test
6. • Try Emergency Heat for 10 minutes. If hot, outdoor unit needs service.
6. Stop and call
7. • Breakers trip again, outdoor coil is a block of ice, or air is still cool after steps 1 to 5.

When Repair vs. Replacement Makes Sense

Consider repair when:

• The system is under 10 to 12 years old.
• The fault is a single component like a capacitor, contactor, or sensor.
• Ductwork is sound and the home’s comfort was fine before the issue.

Consider replacement when:

• The system is 12 to 15 years old with multiple failures.
• The outdoor coil or compressor is compromised.
• Utility bills are rising and comfort is uneven.

We offer same-day estimates and transparent pricing, and can review current rebates and financing. Many homeowners also receive a free first year of Diamond Club with a new system install. Ask our team for current details.

Local Insight: Roanoke Valley Homes

We see patterns in our area that can affect heat output:

• Crawlspace duct issues in older Salem and Vinton homes reduce airflow and heat gain.
• Leaves and needles collect around outdoor units in Goodview and Wirtz, restricting coil airflow.
• Cold snaps across the Blue Ridge can trigger frequent defrost cycles. If defrost is misconfigured, heat suffers.

If these sound familiar, we can target the likely causes first and save you time.

What To Expect When You Call Wisler

• 24/7 availability for urgent no-heat calls.
• Technicians in uniform with name tags and shoe covers.
• A clear, upfront price before work begins.
• A detailed report card of what we tested, cleaned, and adjusted.
• Follow-up recommendations that respect your budget and goals.

Your comfort is the mission. We aim for first-visit fixes with a fully stocked truck and proven process.

What Homeowners Are Saying

"Gave me a better honest quote on a heat pump and air handler than other places in the area did on very similar equipment with same specs without even seeing the previous quotes I got. They were able to send someone out to give me a quote next day and even had it installed before the end of the week...Employees I dealt with from beginning to installation were great and very professional." –Brennan E., Heat Pump Service

"We have been frequent fliers lately and each experience has been positive. Jared was our technician today and repaired our old heat pump. He is a pleasant, skilled professional, answering all our questions as he brought our old system up to code. We are pleased with all the work they have completed on This Ole House. 'Thanks Dad'" –B. H., Heat Pump Service

"Ian came a few days ago for my fall heat pump inspection. He found an issue and needed to order a part. He returned within 48 hours and everything is fixed. Ian was very knowledgeable, professional, and efficient." –Carolyn A., Heat Pump Service

"Nothing worse than heat pump issues in a holiday weekend. Thankful for the awesome folks at Wisler, and for Jared’s excellent skills to get us back up and running." –Heather B., Heat Pump Service

Frequently Asked Questions

Why does my heat pump blow cool air sometimes?

Heat pumps supply warm, not hot, air. In cold weather they may run longer and feel mild. If the air is room temperature or colder for several cycles, or never reaches setpoint, you likely have a fault.

How long should a defrost cycle last?

Most defrost cycles last a few minutes. You may see steam and the outdoor fan stop briefly. If the unit stays iced over for an hour or more, or frequently re-enters defrost, schedule service.

Should I switch to Emergency Heat?

Use Emergency Heat only if the outdoor unit is iced over, damaged, or not heating. It will raise energy use. Switch back to Heat after a technician restores normal operation.

Can low refrigerant cause no heat?

Yes. Low charge reduces heat output and can ice the coil. Only a licensed technician should locate leaks, repair them, and weigh in the proper charge.

How often should I replace my filter?

Check monthly and replace every 1 to 3 months, sooner with pets or construction dust. A clean filter protects the coil, improves airflow, and helps prevent no-heat calls.

Conclusion

If your heat pump is not blowing hot air, start with thermostat, power, airflow, and defrost checks. When symptoms point to refrigerant, controls, or electric heat issues, call a pro. For fast, transparent service in Roanoke, Cave Spring, Salem, and nearby, call (540) 238-0320 or schedule at https://callwisler.com/.

Ready for Same-Day Heat Pump Help?

Call (540) 238-0320 or book at https://callwisler.com/. Ask about our Diamond Club membership for $24 per month that includes up to three complimentary Without Worry Comfort Checks, a reduced $69 service fee, and 10% off repairs. Stay warm tonight with Wisler.

About Wisler Plumbing, Heating, Cooling & Electric

Proudly serving Roanoke and surrounding communities since 1986, Wisler delivers expert HVAC, plumbing, and electrical service. Our NATE-certified technicians arrive in fully stocked vehicles, follow strict safety and cleanliness protocols, and back work with a 100% satisfaction guarantee. We provide 24/7 emergency service, transparent pricing, and our Without Worry Comfort Checks with a written report card. Awards include Angi Super Service and Virginia Business Best Places to Work 2024.