Walkerton, IN Heat Pump Not Cooling? 5 Likely Causes

Estimated Read Time: 8 minutes

Heat pump not cooling? You are not alone. When summer humidity rolls in off Lake Michigan, small issues snowball into warm rooms and high bills. In this guide, you will learn five likely causes, what you can safely check, and when to call Summers Plumbing Heating & Cooling. If you need fast help today, our LaPorte team offers same‑day service and 24/7 emergency support.

1) The outdoor unit is clogged or airflow is restricted

Your heat pump cools by moving indoor heat to the outdoor coil. If the outdoor unit cannot breathe, the system cannot shed heat and rooms stay warm. Two common culprits in LaPorte County are spring cottonwood fluff and grass clippings that mat against the coil.

What you can check now:

1. Clear space: Keep at least 18–24 inches of clearance around the outdoor unit. Trim shrubs, pull weeds, and remove debris on the top grille.
2. Gentle cleaning: With power off at the disconnect, rinse the coil from the inside out using low‑pressure water. Do not bend fins.
3. Straighten fins: A simple fin comb can improve airflow if fins are visibly mashed.

Why pros help: If dirt has migrated deep into the coil, a technician will remove the fan, apply coil cleaner, and rinse thoroughly without flooding electrical components. We also verify the condenser fan motor is running at the correct speed and amperage. Restricted airflow can mimic low refrigerant symptoms, so proper testing matters.

Local‑insider tip: After a windy beach weekend, sand can drift into fenced side yards. A quick visual of the condenser on Monday can prevent a midweek no‑cool call.

2) Incorrect thermostat settings or control issues

Sometimes the fix is simple. If your thermostat is set to Heat, Fan On, or an eco schedule that limits cooling, you will feel warm air. Smart thermostats can also lock you into an “away” profile that caps cooling until you override it.

What you can check now:

1. Mode: Set to Cool and Auto. Lower the setpoint by 3–5 degrees and wait 10 minutes.
2. Batteries: Replace if your thermostat uses them. Low power causes erratic behavior.
3. Schedules: Disable vacation or eco modes. Check that the app and wall unit agree.
4. Airflow: Make sure supply registers are open and not blocked by rugs or furniture.

When to call: If the air handler runs but the outdoor unit will not start, you may have a contactor, capacitor, or control board issue. A shorted low‑voltage wire, failed thermostat relay, or tripped float switch in the condensate pan can also stop cooling. We diagnose these safely and quickly, often the same day.

3) Low refrigerant or a refrigerant leak

Your heat pump relies on a precise refrigerant charge. Too little refrigerant will reduce cooling capacity, cause longer run times, and can ice the indoor coil. Refrigerant does not get “used up,” so a low charge often means a leak.

Warning signs:

1. Weak or warm airflow at vents after a long cycle.
2. Hissing at the indoor or outdoor unit.
3. Ice on refrigerant lines or the evaporator coil.

Why this needs a pro: Handling refrigerant requires EPA certification. Our technicians measure superheat and subcooling, check for leaks, and repair them before recharging. Topping off without fixing the leak wastes money and can harm the compressor.

Efficiency note: New SEER2 testing standards took effect nationwide on January 1, 2023. If your system predates SEER2 by many years and has recurring leaks, a replacement can lower operating costs while bringing you into the current efficiency class.

4) Airflow problems inside the home

Even with a perfect refrigerant charge, poor indoor airflow will undercut cooling. The system needs the right volume of air across the coil to absorb heat.

Common causes:

1. Dirty filter: A clogged filter chokes airflow. Check monthly in summer and replace as needed.
2. Dusty blower wheel: Reduces air volume and increases noise.
3. Collapsed or leaky ducts: Crushed flex duct, disconnected joints, or leaks in attics and crawl spaces waste cold air.
4. Closed returns: Furniture or drapes blocking return grilles starve the system.

What you can do:

1. Install a fresh filter of the correct size and MERV rating your system allows.
2. Open all supply registers at least halfway.
3. Inspect visible duct runs for kinks or disconnects.

What we do on a call: We measure static pressure, temperature split, and blower speed to confirm the system is moving the right amount of air. If static pressure is high, we look for duct restrictions and advise cost‑effective fixes that balance noise, comfort, and energy use.

5) Failed reversing valve, defrost, or aging equipment

Heat pumps rely on a reversing valve to switch between heating and cooling. If the valve sticks or the control fails, your system may stay in the wrong mode. Defrost controls and sensors also affect performance. If the unit cannot manage defrost cycles correctly, it will struggle when humidity is high.

Other reality checks:

1. Age: Most heat pumps last about 10 to 15 years with routine maintenance. Past that window, failures become more likely and parts may be scarce.
2. Sizing: If a previous installer undersized the system, it may never reach setpoint during a heatwave, even if it is “working.”
3. Fan and compressor health: A weak condenser fan or failing compressor drops capacity.

How we solve it: We test valve coil voltage, confirm refrigerant pressures, and verify sensor readings. If the system is near end of life, we provide options, explain SEER2 and HSPF ratings, and outline noise, efficiency, and upkeep tradeoffs so you can make a confident choice.

Quick fixes vs. professional repairs: what is safe to try

Safe homeowner steps:

1. Replace the air filter and clear return grilles.
2. Hose off the outdoor coil with power off.
3. Confirm thermostat mode, setpoint, and schedules.
4. Reset breakers once. If it trips again, stop and call.

Call a pro if you notice:

1. Ice on the lines or coil.
2. Burning or electrical smells.
3. Frequent cycling on and off.
4. Water under the indoor unit.

Our diagnostic includes electrical testing, refrigerant analysis, airflow measurements, and a clear, itemized estimate before work begins.

Prevent the next no‑cool: maintenance that actually matters

Twice‑a‑year tune‑ups are the best defense in our lake‑effect climate. We recommend one visit in spring before cooling season and one in early fall before heating. During your visit, we:

Remove dirt and debris from the outdoor condenser and indoor components Check refrigerant levels and inspect for signs of leaks Calibrate your thermostat to ensure accurate temperature control Inspect and tighten all electrical wiring and safety controls Lubricate moving mechanical parts to reduce friction and wear Clear the condensate drain line to prevent water damage or mold growth Test the reversing valve and defrost settings for safe transitioning between heating and cooling Replace or clean air filters for improved indoor air quality

Membership perks: Our maintenance plans include two professional tune‑ups each year, priority scheduling anytime service is needed, and discounts on repairs and parts. Members also receive reminders, so heat pump care is never left to chance.

When a replacement is the smarter move

If your unit is 12+ years old, has a history of leaks, or needs a major part such as a compressor, it may be time to compare repair vs. replace. Here is how we guide you:

1. Right‑sizing: We perform a proper load calculation, not a guess.
2. Efficiency clarity: We explain SEER2 and HSPF in plain terms and estimate energy savings.
3. Comfort goals: We discuss noise levels, zoning with mini‑splits, and dehumidification.
4. Ownership costs: We outline warranty, maintenance, and likely lifespan.

We handle everything from removal to wiring or duct adjustments, then we test the new system and walk you through operation before we leave.

Why homeowners in LaPorte choose Summers for heat pump cooling issues

Experience: We have served the LaPorte area since 1969 with fully licensed, insured, and background‑checked technicians.

Anytime help: True 24/7 emergency response when your system quits after hours.

Transparency: No hidden fees and clear, itemized estimates. We can match or beat competitors’ prices on comparable services.

End‑to‑end support: From fast repairs to seasonal tune‑ups and full replacements, we keep your system efficient and reliable all year.

What Homeowners Are Saying

"Our tech Frank Brown provided one of the most professional experiences possible. He was helpful with questions, straight to the point, and didn’t show up just to try selling something even though we ended up needing a whole new system. Thank you Frank!"
–Frank B., Whole system replacement

"Rob Kucharski, as the technician, was responsive to my furnace problem, and replaced a part that is necessary for the furnace to operate. I was grateful to have heat again quickly, and he told me of their maintenance service to prevent this sort of thing from happening in the future."
–Rob K., Furnace repair

Frequently Asked Questions

Why is my heat pump running but not blowing cold air?

Thermostat mode, a dirty filter, or a clogged outdoor coil can limit cooling. If airflow and settings look fine, low refrigerant, a failed capacitor, or a control issue may be the cause. Schedule a diagnostic to confirm.

Is it normal for my heat pump to run a long time in summer?

Yes during peak heat, but it should still reach setpoint. Long, ineffective cycles point to airflow restrictions, a dirty coil, low refrigerant, or undersizing. A pro can measure static pressure and refrigerant performance.

Can I hose off my outdoor unit?

Yes. Turn power off at the disconnect and use low pressure from the inside out. Avoid bending fins and do not spray electrical panels. If debris is packed deep, call a technician for a proper cleaning.

How often should I service my heat pump?

In our climate, twice per year. Schedule a spring cooling tune‑up and a fall heating tune‑up. This catches refrigerant issues, protects the compressor, and keeps efficiency high.

When should I replace instead of repair?

Consider replacement if the unit is 12–15 years old, has repeated leaks, or needs a major part like a compressor. New SEER2 systems can cut energy costs and improve comfort and noise levels.

In Summary

If your heat pump is not cooling, start with airflow and settings, then call for a proper diagnostic before parts fail. Summers Plumbing Heating & Cooling helps LaPorte‑area homeowners fix issues fast and prevent repeat breakdowns with tuned, SEER2‑ready solutions.

Ready to get cool air flowing again?

Call Summers Plumbing Heating & Cooling at (219) 349-0509 or book online at https://www.summersphc.com/la-porte/ for same‑day heat pump repair, tune‑ups, or a free replacement estimate. Mention you saw this guide when you schedule.

About Summers Plumbing Heating & Cooling Serving LaPorte County since 1969, Summers delivers certified HVAC service with price‑match value, upfront estimates, and 24/7 emergency response. Our technicians are licensed, insured, background checked, and trained on today’s SEER2 standards and heat pump technology. We stand behind our work with solid warranties, careful installs, and clear walkthroughs. Twice‑a‑year tune‑ups, priority scheduling for members, and honest repair advice make comfort simple and affordable.