Lafayette, IN Heat Pump Not Cooling? 5 Key Reasons

Estimated Read Time: 9 minutes

If you’re searching for help with a heat pump not cooling, you’re not alone. When your home feels muggy and the thermostat won’t budge, every minute matters. Below are the top reasons your system falls short in Lafayette’s summer humidity, quick fixes you can try today, and clear signs it’s time to call Summers Plumbing Heating & Cooling for same-day service. We’ll help you avoid guesswork, protect your equipment, and restore cool comfort fast.

First, a 60-second refresher: how heat pumps cool

A heat pump doesn’t create cold. It moves heat outdoors using refrigerant, a compressor, coils, and fans. When something restricts airflow or refrigerant flow, heat can’t leave your home. The result is weak cooling, long run times, high bills, and rooms that never feel comfortable.

Local note: In Greater Lafayette, West Lafayette, and Frankfort, heavy summer humidity makes airflow issues and clogged drains more common. Keeping air moving and coils clean is key.

Reason 1: Thermostat settings or mode are incorrect

Your thermostat may be set to Heat, Fan On, an energy-saving schedule, or the wrong temperature sensor. Some smart stats also switch modes based on “eco” logic.

Try this:

1. Set mode to Cool and Fan to Auto. Target 72–75°F for testing.
2. Disable schedules and Hold your setpoint for 2–3 hours.
3. Check for a dead thermostat battery or loose wires.
4. Verify your heat pump lockout/balance settings in the app.

Call a pro if the system short cycles or the outdoor unit never starts. That usually points to a control board, capacitor, or safety switch problem.

Review snippet: “Very happy with the service from Summers!”

Reason 2: Dirty filters or coils are choking airflow

Restricted airflow is the most common reason a heat pump fails to cool. A clogged filter starves the indoor coil, which can ice over and block cooling. Dirty indoor or outdoor coils act like a winter coat on the system, trapping heat.

Quick fixes:

1. Replace the air filter now. Use MERV 8–11 unless your system is designed for higher.
2. Rinse the outdoor coil with a gentle hose spray from the inside out. Power washers bend fins.
3. Clear 2–3 feet of space around the outdoor unit and trim plants.

Professional cleaning restores performance, reduces compressor strain, and lowers bills. Our techs also inspect drain pans and clear the condensate line so humidity actually leaves your home.

Review snippet: “Cleaned up and you would never know they did a major project for us.”

Reason 3: Low refrigerant or a refrigerant leak

Your heat pump must have the right refrigerant charge to move heat. Low charge means the system can run all day with little cooling, ice formation, and rising energy use. Topping off without leak detection is a short-lived fix that risks compressor failure.

What you can do:

1. Look for icing on the refrigerant lines or indoor coil.
2. Listen for hissing near connections.
3. Do not try to add refrigerant yourself. It requires EPA-certified handling.

What we do:

1. Measure superheat/subcooling to verify charge.
2. Perform electronic leak detection and dye testing when needed.
3. Repair leaks and recharge to manufacturer spec.

Review snippet: “I called for a second opinion on a replacement part on a heat pump that was misdiagnosed by another company.”

Reason 4: Outdoor unit problems blocking heat removal

If the outdoor fan is not running, blades are damaged, or fins are bent, your system cannot reject heat to the outside air. Debris, mulch, cottonwood, and pet hair can pack the coil and suffocate performance.

DIY steps:

1. Shut power off. Remove leaves and debris from the cabinet.
2. Gently straighten bent fins with a fin comb.
3. Restore power and confirm the fan runs smoothly.

Professional steps:

1. Inspect capacitors, contactors, fan motors, and wiring for wear.
2. Test motor amperage vs. nameplate.
3. Deep-clean coil surfaces for full heat transfer.

Review snippet: “Arrived on time to install a heat pump, air handler, and mini split system… explained how the system would work.”

Reason 5: Duct leaks or a failing air handler/blower

Up to 20–30 percent of cooled air can be lost through leaky or uninsulated ducts, especially in attics and crawlspaces. If the blower is weak, dirty, or failing, airflow drops and rooms go warm. Signs include hot bedrooms over the garage, dusty vents, and rattling or whistling sounds.

What helps:

1. Duct inspection and sealing at joints, boots, and returns.
2. Blower wheel cleaning and motor testing.
3. Correcting undersized returns or closed supply vents.

Our Lafayette teams also check static pressure to confirm the duct system matches your heat pump’s airflow needs.

Review snippet: “Gone through this company for duct repairs… helped me to find a good company to finance at a very fair rate.”

Repair or replace: how to decide

Choose repair when:

1. The unit is under 10–12 years old and has a clear, isolated fault.
2. The coil or fan is dirty, the capacitor is weak, or charge is slightly low.

Consider replacement when:

1. The compressor is failing or repairs exceed 30–40 percent of replacement cost.
2. You have repeated leaks, poor comfort, and rising bills.
3. You want higher SEER2 efficiency, quieter operation, or better humidity control.

We install and service all types, including geothermal and ductless mini-split systems. Free second opinions help you compare options with confidence.

What a pro tune-up includes in Greater Lafayette

Annual maintenance is the fastest way to prevent no-cool surprises. Our checklist includes:

1. Inspect the condenser unit and clear debris.
2. Check ductwork for leaks or damage.
3. Function check the thermostat and controls.
4. Inspect and clean indoor and outdoor coils.
5. Top off refrigerant to spec after leak verification.
6. Inspect wiring and harnesses; test capacitors and contactors.
7. Straighten fins and verify fan operation.
8. Inspect the drain pan and clean the drain line.
9. Confirm proper cycling and temperature split across the coil.
10. Replace the filter.

We recommend scheduling before summer. Many Lafayette homeowners pair this with our maintenance plan for reminders, priority service, and savings.

When to call for same-day service

Call immediately if you notice:

1. Ice on the lines or coil in hot weather.
2. Burning smells or repeated breaker trips.
3. Continuous running with little airflow at vents.
4. Water around the indoor air handler.

Summers provides 24/7 emergency service, upfront pricing you approve before work starts, and fully stocked trucks to finish most repairs in one visit.

Local insight: comfort tips for Lafayette humidity

1. Keep your fan set to Auto, not On. Auto dehumidifies better.
2. Do not close too many supply vents. It raises static pressure and causes icing.
3. Keep 2–3 feet of clearance around your outdoor unit. Cut back ivy and shrubs.
4. Replace filters every 1–3 months during peak cooling.

These simple habits protect your system and help it handle muggy July afternoons in West Lafayette, Battle Ground, and Rossville.

Frequently Asked Questions

Why is my heat pump running but not cooling?

This usually points to airflow restrictions, incorrect thermostat settings, or low refrigerant. Start with a fresh filter and confirm Cool/Auto on the thermostat. If vents are weak or lines are icy, shut the system off and call for service to prevent compressor damage.

Should I turn off the heat pump if the outdoor unit is iced up in summer?

Yes. Turn the system off at the thermostat and let it thaw. Running while iced can harm the compressor. Replace the filter, check for blocked returns, and schedule service to check charge, airflow, and the condensate drain.

How often should a heat pump be serviced?

Once per year for cooling and once before heating is ideal. At minimum, schedule annual service before summer. Professional tune-ups clean coils, verify refrigerant, test electrical parts, and clear drains to stop no-cool emergencies.

Can leaky ducts really make rooms feel hot?

Yes. Duct leaks can waste 20–30 percent of cooled air, especially from attic or crawlspace runs. Sealing joints, repairing crushed flex, and adding returns improves airflow, lowers bills, and restores even temperatures across rooms.

When is replacement better than repair?

If the unit is older than 12 years, has a failing compressor, or repair costs exceed 30–40 percent of replacement, consider upgrading. New systems deliver higher SEER2 efficiency, improved humidity control, and quieter operation. We offer free second opinions and financing.

In Summary

If your heat pump not cooling your home is disrupting your day, start with simple checks, then call the pros for safe diagnostics. Summers Plumbing Heating & Cooling keeps Lafayette homes comfortable with same-day service, upfront pricing, and technicians trained to fix it right the first time. We service heat pumps, mini-splits, and geothermal systems across West Lafayette, Frankfort, and beyond.

Ready to restore your cooling?

Call Summers Plumbing Heating & Cooling at (765) 262-5364 or book online at https://www.summersphc.com/lafayette/ for same-day heat pump service. Get a free second opinion on major repairs or replacement quotes. Your comfort comes first—schedule now and stay cool today.

About Summers Plumbing Heating & Cooling

Serving Lafayette since 1969, Summers Plumbing Heating & Cooling provides neighborly, expert HVAC service with drug-tested, background-checked, and licensed technicians. We offer upfront pricing, free second opinions, 24/7 emergency response, and fully stocked trucks for faster fixes. Our team services all heat pump types, including geothermal and mini-splits, and we stand behind our work with strong guarantees and flexible financing options. Local homeowners trust us for honest advice, reliable repairs, and maintenance plans that keep systems efficient all year.