November 3, 2025
Kokomo Heat Pump Not Cooling? 5 HVAC Fixes
Estimated Read Time: 10 minutes
If your heat pump is not cooling, you are not alone. Kokomo summers bring sticky humidity and long warm spells. In this guide, we explain why a heat pump not cooling happens, how to troubleshoot safely, and when to call a pro. You will get clear steps to protect your system and lower bills, plus local insights to keep your home comfortable all season.
Reason 1: A clogged or incorrectly sized air filter is choking airflow
Your heat pump depends on steady airflow across the indoor coil. A clogged filter starves airflow, the coil cannot absorb heat, and your home feels warm even when the system runs. If the filter is the wrong size or installed backward, the problem is the same: low airflow and poor cooling.
What to check now:
- Turn off the system at the thermostat.
- Remove the filter at the return grille or air handler.
- If it looks gray or covered in dust, replace it. Use the correct dimensions and an appropriate MERV rating recommended by your technician.
Pro insight:
- Replacing a dirty filter can reduce cooling energy use by 5 to 15 percent.
- In homes with pets or construction dust, check filters monthly in summer.
- If you see ice on the indoor coil or refrigerant lines, leave the system off and call for service after the ice melts.
Local tip for Kokomo and nearby cities: Pollen and field dust spike along US‑31 and open areas around Howard County. During peak counts, the filter can clog faster than usual.
Reason 2: Thermostat or mode settings are incorrect
It is easy to overlook a simple setting when your home is hot. If your thermostat is set to Heat, or on Auto mode with a high set point, the system will not cool. Fan settings can also mislead you. On Fan On, air will move but cooling may not be active.
Quick checks:
- Set the thermostat to Cool and 3 to 5 degrees below current room temperature.
- Set the fan to Auto so the blower cycles with the compressor.
- If you have a heat pump with emergency heat, confirm that EM Heat is off during summer.
Signs you need a pro:
- The thermostat screen is blank or flickers.
- The outdoor unit does not start even with a cooling call.
- You use a new smart thermostat and the wiring was never configured for a heat pump.
Professional note: Many smart thermostats need specific heat pump wiring and configuration. A common issue is incorrect O/B reversing valve setting. If set wrong, the system can heat when you request cooling.
Reason 3: Low refrigerant or a refrigerant leak
A heat pump that is not cooling often has low refrigerant charge. Refrigerant does not get used up. If it is low, there is a leak. Low charge reduces heat transfer, lengthens run times, and can freeze the coil. Left alone, the compressor may be damaged.
What you might notice:
- Warm air from vents after 10 minutes of operation.
- Ice on the small copper line or the indoor coil.
- Hissing near the indoor or outdoor unit.
What not to do:
- Do not try to add refrigerant yourself. Federal law requires EPA Section 608 certified technicians to handle refrigerants.
- Do not chip ice off the coil. Allow it to melt naturally to avoid damage.
How a technician resolves it:
- Inspect for oil stains that indicate a leak.
- Perform electronic, soap bubble, or nitrogen tests to locate the leak.
- Repair or replace the leaking component, evacuate, and charge to manufacturer specs.
- Verify superheat and subcool readings to confirm proper charge.
When repair vs. replace makes sense: If the leak is in a corroded coil on an aging unit, a modern high efficiency heat pump may be the smarter move. Summers can show energy and comfort gains and offer financing to keep payments predictable.
Reason 4: Frozen indoor coil or other airflow restrictions
A frozen coil is a symptom, not the cause. It usually comes from low airflow or low refrigerant. In Kokomo’s humid summers, a small airflow issue can snowball into a frozen block of ice on the coil.
Common triggers:
- Dirty filter or blower wheel
- Closed supply registers or blocked returns
- Collapsed or kinked duct runs
- Dirty evaporator coil
Safe steps to take:
- Turn the thermostat to Off and set the fan to On to speed thawing.
- Place towels where condensation may drip while ice melts.
- After thawing, replace the filter and reopen all supply registers.
Why this matters: Ice reduces airflow further, which stresses the compressor and can cause water damage when it melts. If ice returns within 24 hours, schedule a diagnostic. There may be a deeper issue such as a weak blower motor, undersized return, or refrigerant problem.
Reason 5: Outdoor unit issues, from dirty coils to blocked fans
Your outdoor unit releases heat from your home. If the coil is clogged with cottonwood fluff, grass clippings, or road dust, it cannot reject heat and your heat pump will not cool well.
What to look for outside:
- Debris drawn against the coil fins
- Shrubs or fences closer than 18 to 24 inches
- A fan that starts late, runs slowly, or stops mid cycle
- Loud buzzing from a failing capacitor or contactor
DIY maintenance you can do:
- Shut power off at the disconnect.
- Gently rinse the coil from the inside out with a garden hose. Avoid pressure washers.
- Keep clear space around the unit for airflow.
Why a technician helps: If components are failing, testing is needed. A pro checks capacitor microfarads, fan motor amp draw, coil condition, and the system’s running pressures. Small parts can prevent a midsummer breakdown if replaced early.
Extra causes that mimic a cooling problem
Even if the system is healthy, other issues can make the home feel warm:
- Leaky ducts in attics or crawl spaces can dump cool air outside.
- Oversized units short cycle and never dehumidify properly.
- Poor insulation and attic ventilation allow heat soak during late afternoon.
A Summers inspection can pressure test your ducts, measure static pressure, and right size equipment if replacement is on the table. Our team has served Indiana homes since 1969, so we know how to tackle humidity swings that come with thunderstorms and crop field evaporation.
Safe troubleshooting checklist for homeowners
Use these steps before you call. If any step reveals a serious issue, stop and schedule service.
- Confirm the thermostat is on Cool and set 3 to 5 degrees below room temperature.
- Replace a dirty filter and open all supply registers.
- Check your outdoor disconnect is on and the breaker is not tripped.
- Clear debris from the outdoor coil and ensure 18 inches of clearance.
- If you see ice, turn the system off and let it thaw before restarting.
If the heat pump is not cooling after these steps, a licensed tech should check refrigerant levels, electrical parts, and the blower system.
Prevent problems with smart maintenance
Regular maintenance protects comfort and avoids high bills. Summers offers HVAC service plans that include inspections, tune ups, and cleanings. A precision tune up checks airflow, electrical parts, refrigerant levels, drain lines, and coil cleanliness. These steps prevent breakdowns and can extend the life of your system.
Two helpful facts:
- Our team provides 24/7 emergency heating and cooling service for urgent problems.
- Routine maintenance with clean filters and coils reduces wear on the compressor, the most expensive part of your heat pump.
When you stay ahead of dirt, debris, and minor electrical wear, your heat pump will cool better, last longer, and cost less to operate.
When to repair and when to replace
Repair is usually best when:
- The system is under 10 years old and the fix is minor.
- The refrigerant leak is small and accessible.
- Parts are readily available and under warranty.
Replacement is often smarter when:
- The compressor or coil is failing on an older system.
- The system uses an older refrigerant and parts are scarce.
- Energy bills keep climbing even after maintenance.
A new high efficiency heat pump can improve comfort and reduce electricity use. Summers installs modern, energy efficient systems and can add zoning to fix hot and cold rooms. We also offer flexible financing to make upgrades affordable.
Why choose a licensed local pro for cooling issues
Working with a licensed HVAC contractor protects your home and equipment. Refrigerant handling requires EPA Section 608 certification, and many Indiana municipalities require mechanical permits for replacements. A proper diagnostic uses gauges, temperature probes, and electrical tests. It confirms the real cause so you do not waste money on guesswork.
Summers Plumbing Heating & Cooling has served Kokomo, Marion, Logansport, Frankfort, and nearby communities for decades. We match or beat competitor pricing, arrive with the right tools, and give you clear options. If your heat pump is not cooling, we will fix the root cause, not just the symptom.
What Homeowners Are Saying
"Kris Polk is the man. He came out today and diagnosed my heat pump in a timely manner. I highly recommend Summers PHC."
–Tom W., Kokomo
"We had Kristopher our today to service out heat pump. He was very professional and didn't force us into anything we didn't want for our system."
–Vincent D., Kokomo
"Summers evaluated and estimated the cost of changing my air source heat pump system. Tech Josh was very knowledgeable, polite, and professional. He took all the time necessary to explain everything and answer all of my questions. Great company to work with."
–Thomas B., Kokomo
"Summers has installed our furnace and heat pump, water pump, water heater and cleaned our ducts."
–Ellen S., Kokomo
Frequently Asked Questions
Why is my heat pump not cooling but the fan runs?
The fan can move air even when the outdoor unit is not cooling. Check thermostat mode, replace the filter, and ensure the outdoor unit runs. If it does not, call for service.
Can a dirty filter cause my heat pump to freeze up?
Yes. A clogged filter reduces airflow and can freeze the indoor coil. Turn the system off, let ice melt, replace the filter, and schedule service if it happens again.
How long should a heat pump take to cool my home?
In normal conditions, you should feel cooler air within 10 minutes and see room temperatures drop 1 to 2 degrees per hour. High humidity can slow this slightly.
Should I hose off my outdoor unit?
Yes, gently. Turn power off and rinse from the inside out with a garden hose. Avoid high pressure. If the coil is matted with debris, schedule a professional cleaning.
When should I replace rather than repair?
Consider replacement if your system is old, has a major leak or compressor failure, or needs frequent repairs. A new efficient unit can improve comfort and lower bills.
Bottom Line
A heat pump not cooling usually comes down to airflow, settings, refrigerant charge, frozen coils, or outdoor unit issues. A quick check of filters, thermostat, breakers, and debris may restore cooling fast. For deeper faults, call a licensed pro.
Call to Schedule
If your heat pump is not cooling in Kokomo or nearby cities, call Summers Plumbing Heating & Cooling at (765) 252-0727 or book online at https://www.summersphc.com/kokomo/. 24/7 emergency service available. Ask about maintenance plans to prevent breakdowns and keep your system efficient.
Ready for cool comfort? Call (765) 252-0727 or schedule at https://www.summersphc.com/kokomo/ today.
About Summers Plumbing Heating & Cooling
Locally owned since 1969, Summers Plumbing Heating & Cooling delivers honest pricing, 24/7 emergency response, and a Worry‑Free Guarantee. Our licensed HVAC pros are trained on modern heat pump technology and follow EPA Section 608 rules for refrigerants. We match or beat competitor pricing, offer flexible financing, and stand behind our work. From precision tune ups to full heat pump replacements, homeowners across Kokomo and nearby cities trust Summers for fast, friendly, and reliable service.