Indianapolis Heat Pump Not Blowing Hot Air? HVAC Fixes

Estimated Read Time: 11 minutes

A heat pump not blowing hot air can feel urgent on a freezing Indiana morning. Before you panic, run through this simple checklist to diagnose the most common causes and get warm air moving again. This guide shows you what to check, what to adjust, and when to call a pro. You will also see how regular maintenance prevents repeat breakdowns and high energy bills.

Why your heat pump might stop blowing hot air

Heat pumps move heat, they do not create it. When they stop delivering warm air, the root cause is usually settings, airflow, defrost, or a developing mechanical issue. Start with quick, safe checks before you assume the worst.

Common categories to consider:

1. Thermostat mode, set point, and schedules
2. Airflow restrictions and filter issues
3. Outdoor unit blocked or in defrost
4. Refrigerant charge problems or leaks
5. Electrical and control faults
6. Special cases for ductless and dual-fuel systems

Two helpful facts to keep in mind:

• Heat pumps often blow air that feels cooler than furnace supply air. Supply temperatures around the mid-90s can still heat your home.
• Because they heat and cool, they run all year. That is why pros recommend biannual service in spring and fall.

Quick safety and warranty checks

Before you open panels, confirm the basics. Many no-heat calls are solved here.

• Confirm power: check the indoor breaker and the outdoor disconnect. Reset tripped breakers once. If they trip again, call a pro.
• Look for error codes: your thermostat or indoor unit may show a fault number. Note it for the technician.
• Respect warranty rules: opening sealed compartments or handling refrigerant can void warranties. If you are unsure, stop and schedule service.
• Consider the weather: in central Indiana, frost and freezing rain can build up fast. A light frost is normal, but a solid ice block is not.

If you notice burnt smells, buzzing from electrical panels, or visible arcing, shut the system off and call for emergency service.

Thermostat and mode settings

Mode errors are the most common reason a heat pump is not blowing hot air.

• Confirm you are in Heat mode, not Cool or Auto. Auto can bounce between modes and feel lukewarm.
• Raise the set point 3 to 5 degrees above room temperature to trigger a steady heat call.
• Check schedule or eco settings. A setback schedule can limit heat output and fan speed.
• If you have a smart thermostat, verify the heat pump type, reversing valve setting (O/B), and auxiliary heat configuration. Incorrect settings can block the backup heat stage.

Reset the thermostat if needed. Pull the batteries or use the device reset, then re-enter your preferred schedule. If you see “Aux” or “Emergency Heat,” the system may be using backup heat because the primary heat pump is not keeping up.

Airflow and filter issues

Restricted airflow makes supply air feel cool even if the system is heating. It also increases energy use.

• Filter: check now. If it is dirty or older than 60 to 90 days, replace it. Homes with pets may need monthly changes.
• Vents and returns: open all supply registers and keep furniture or rugs 12 inches away. Clear return grilles of dust and debris.
• Indoor coil: excessive dust reduces heat transfer. If the coil is visibly dirty, schedule a professional cleaning.
• Blower speed: some systems allow a higher heating fan speed. A pro can optimize CFM to balance comfort and noise.

If airflow improves, you should feel warmer air within minutes.

Outdoor unit and defrost cycle

In cold weather, outdoor coils collect frost. Your heat pump will run a defrost cycle that can temporarily blow cooler air inside.

What normal defrost looks like:

• Steam around the outdoor unit
• Louder fan change or compressor pitch shift
• Brief periods of cooler indoor air

Abnormal signs to watch for:

• A block of ice around the outdoor unit
• Fan not spinning or grinding noises
• Defrost every few minutes without very cold weather

Keep the outdoor unit clear:

1. Remove snow or leaves around the unit, at least 2 feet of clearance on all sides.
2. Gently rinse coils with a garden hose if they are dirty and the weather allows. Do not pressure wash.
3. Make sure downspouts do not dump water onto the unit, which can create ice.

If ice builds into a solid mass, shut the system off and call for service.

Refrigerant and possible leaks

Low refrigerant reduces heat transfer and makes supply air feel cool. Only a licensed technician can measure superheat or subcooling and add refrigerant.

Warning signs include:

• Hissing or gurgling from the indoor or outdoor unit
• Ice on the refrigerant lines or coil outside of normal frost
• Longer run times with poor heating

A technician will check for leaks, repair the issue, and recharge the system according to specifications. We pay attention to modern efficiency ratings like SEER2 and HSPF when advising repair versus replace. If your unit is older and inefficient, a repair may not be your best long-term value.

Electrical connections and controls

Loose wires, weak capacitors, or failing sensors can stop the heat pump from heating even when the fan runs.

• Cycle power at the breaker to clear minor control glitches.
• Listen for the outdoor compressor. If the indoor blower runs but the compressor is silent, you may have a contactor or capacitor issue.
• If lights flicker when the unit starts, have a professional check amps and the electrical whip.

Because electrical issues can escalate, do not open panels unless you are trained. Our licensed and background-checked technicians can diagnose safely and quickly.

Ductless mini-split not blowing hot air

Mini-splits have unique checks.

• Set mode to Heat, not Auto. Confirm the vane angle directs air downward in heating.
• Clean the washable filters every 4 to 6 weeks. Dust buildup sharply reduces heat output.
• Inspect outdoor wall brackets for ice buildup below the unit. Clear safe drainage paths.
• Use the manufacturer’s remote to run a manual defrost if available.

If multiple indoor heads do not heat, the issue may be with the outdoor inverter board, sensors, or refrigerant charge. A pro will retrieve error codes from the unit to pinpoint the exact fault.

Dual-fuel and backup heat considerations

In dual-fuel systems, a heat pump pairs with a gas furnace. If you only feel cool air, your switchover temperature could be set too low or the call to the furnace may be disabled.

Check the thermostat configuration:

1. Confirm the heat pump is primary with gas as backup.
2. Verify the balance point or outdoor lockout temperature. If it is set too low, the system may not switch to gas when it should.
3. Make sure the outdoor temperature sensor is working and reading accurately.

For electric auxiliary heat strips, ensure breakers feeding the heater kit are on. If Aux never engages, the home may never warm up on very cold nights.

Hot air feels lukewarm at the register

Heat pumps aim for steady, even heat rather than blasts of very hot air. That can still be normal heat.

Try these quick tests:

• Use a thermometer at the return and the nearest supply. A 15 to 30 degree rise is common depending on outdoor temperature.
• Let the system run for 15 minutes after you change a setting before judging.
• Close excessive unused rooms. Over-closing can reduce airflow and comfort.

If the temperature rise is low after filter and coil checks, call for diagnostics.

When to call a professional in the Brownsburg area

DIY checks are great, but some problems need licensed tools and training.

Call us if you notice:

• Ice block on the outdoor unit or repeated defrost cycles
• Hissing, gurgling, or oily residue near linesets
• Breakers that trip again after a reset
• No compressor sound outdoors while the indoor fan runs
• Error codes on the thermostat or indoor display

Summers Plumbing Heating & Cooling provides full lifecycle heat pump support: new installation, replacement, repair, seasonal tune-ups, and 24/7 emergency service. We service air-source, ductless mini-split, dual-fuel, and geothermal systems. We also offer transparent estimates, flexible financing, and strong warranties.

We know Hendricks County homes and the Indy metro well, from Brownsburg and Avon to Whitestown and Zionsville. Our service vehicles are stocked for common repairs so most homes get heat restored in one visit.

Prevent repeat issues with maintenance

Because heat pumps operate all year for both heating and cooling, the best approach is to have tune-ups twice a year. During a professional tune-up, we follow a thorough checklist to keep performance and efficiency high.

“The basic steps of a professional tune-up include: Cleaning the indoor and outdoor coils to optimize energy efficiency, checking refrigerant levels and looking out for possible leaks, inspecting and tightening all electrical connections, calibrating the thermostat for accurate temperature control, lubricating moving parts to reduce friction, clearing the condensate drain line to prevent water damage, testing the defrost feature and reversing valve for proper operation, and changing or cleaning air filters.”

Benefits you will notice:

• Lower energy bills thanks to restored heat transfer
• Fewer surprise breakdowns because small issues are found early
• Longer equipment life and stronger winter performance
• Cleaner indoor air by controlling dust and moisture

“If you sign up for a maintenance plan, our team will remind you when it’s time for your next service and offer priority scheduling so you never have to worry.”

Step-by-step quick checklist you can try today

Work through these in order. Many no-heat calls are solved before we roll a truck.

1. Set thermostat to Heat and raise set point 3 to 5 degrees.
2. Replace or clean the air filter. Open all supply and return vents.
3. Check breakers inside and the outdoor disconnect. Reset once.
4. Look outside for ice or debris. Clear snow and leaves. Do not chip ice.
5. Listen for the outdoor compressor and indoor blower. Note any error codes.
6. If the system blows cool air for longer than 20 minutes or short cycles, call a pro.

Repair or replace: making the smart call

If your heat pump is 10 to 15 years old, struggles to heat, and has a refrigerant or compressor issue, a replacement may be smarter than a major repair. We help you compare total cost of ownership, not just today’s bill.

What we evaluate during an in-home assessment:

• Insulation levels, square footage, and window orientation
• Duct condition and static pressure
• Usage patterns and comfort goals
• Local electric and gas rates

We pay attention to modern efficiency ratings such as SEER2 and HSPF and consider quiet operation and smart thermostat compatibility. You will get a clear, upfront quote before any work starts, with options for financing.

Geothermal and special systems

If you have a geothermal heat pump, do not assume the troubleshooting steps are the same as air-source. Loop pressure, flow rate, and water temperature must be checked by a trained technician. We service and replace geothermal systems as part of our full-scope capability.

Whole-home comfort matters

Heat pump performance ties into air sealing, duct quality, and indoor air quality. If you have persistent cold rooms or humidity swings, we can test and balance your system and pair the right accessories for stable comfort. Because Summers provides HVAC, plumbing, and IAQ service, you get a single partner for a complete, efficient home.

What to expect when we visit

• Prompt arrival with fully stocked vehicles to minimize delays
• A clear diagnosis and simple explanation before any work begins
• Options for repair or replacement with transparent pricing
• Respect for your home with shoe covers and clean work areas

We stand behind our work with strong warranties and 24/7 availability, so you are never left without help on a cold night.

Service area

We proudly serve Brownsburg, Indianapolis, Plainfield, Zionsville, Avon, Lebanon, Whitestown, Danville, Pittsboro, and Jamestown. If you live nearby, call and we will let you know our earliest appointment time.

What Homeowners Are Saying

"Needed a second opinion on a heat pump repair/replace decision. Josh came out and did a nice thorough investigation, explained things in an easy to understand way and the gave his recommendation....which knowingly steered me back to the other company I was working with. It was extremely refreshing to experience a totally honest and unselfish interaction. ... Now that the gremlins have been vanquished, the unit has worked flawlessly."
–Homeowner, Heat Pump Repair

"We had a really great experience with Summers installation of our heat pump water heater. Heather was extremely knowledgeable and courteous. The installation was quick and painless. We will definitely be using their services again."
–Homeowner, Heat Pump Installation

Frequently Asked Questions

Why does my heat pump blow cool air during winter?

Heat pumps deliver steadier, lower-temperature air than furnaces. During defrost, indoor air may feel cooler for a few minutes. If it never warms, check filters, mode, and call a pro.

How often should a heat pump be serviced?

Twice a year. Because heat pumps run for heating and cooling, spring and fall tune-ups keep efficiency high and prevent winter breakdowns.

How long should a heat pump run before I feel warmer air?

Give it 10 to 20 minutes after changing the set point. If supply air still feels cool and your filter is clean, schedule diagnostics.

Can low refrigerant cause no heat?

Yes. Low refrigerant reduces heat transfer and can ice the coil. Only a licensed technician can find leaks and recharge to spec.

When should I switch to auxiliary or emergency heat?

Use Aux when the heat pump cannot maintain set point in severe cold. Use Emergency Heat only if the heat pump has failed and you need temporary heat until service arrives.

Recap

A heat pump not blowing hot air usually traces back to settings, airflow, defrost behavior, or a developing mechanical problem. Work through the quick checks above, and if issues persist, we are ready to help across Brownsburg and the greater Indianapolis area.

Call to Schedule

Need fast, local help today? Call Summers Plumbing Heating & Cooling at (317) 765-1855 or schedule online at https://www.summersphc.com/brownsburg/. Ask about our biannual tune-up plan for priority scheduling and year-round comfort.

Call now: (317) 765-1855 | Book online: https://www.summersphc.com/brownsburg/ | Ask about maintenance plans for priority scheduling and year-round savings.

About Summers Plumbing Heating & Cooling

For more than 40 years, Summers Plumbing Heating & Cooling has helped Hoosier homeowners with honest advice, clear pricing, and lasting HVAC solutions. We are locally owned, 100% employee owned, licensed, and background checked. Our technicians service all major heat pump brands, including ductless and dual-fuel systems. You get upfront estimates, strong warranties, priority scheduling with maintenance plans, and 24/7 emergency response across Hendricks County and the Indy metro.