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November 3, 2025

Columbus, TX Heat Pump Not Cooling? 5 Likely Causes

Estimated Read Time: 9 minutes

If your heat pump is not cooling, you feel it fast. Hot rooms, long run times, and higher bills are a bad combo. In Central Texas, humidity makes it worse. This guide covers the top five reasons your heat pump stops cooling, the quick checks you can do, and when to call the pros. We will help you get steady, efficient cooling without guesswork. Mention our $55 Heat Pump Check-Up if you want a pro safety net.

How a Heat Pump Cools: A 60-second Primer

A heat pump moves heat, it does not create it. In cooling mode, it absorbs indoor heat at the evaporator coil and releases it outside at the condenser. Refrigerant carries that heat. Airflow pushes energy across the coils. The thermostat and control board decide mode and staging. If any link breaks, cooling falls off. Knowing these basics helps you pinpoint the issue and speak the same language as a technician.

Key parts that matter for cooling:

  1. Thermostat and control board that command cooling.
  2. Refrigerant circuit: compressor, coils, metering device.
  3. Airflow system: indoor blower, outdoor fan, clean filters, clear return grilles.
  4. Reversing valve that switches heat to cool.

Reason 1: Wrong Thermostat or Mode Settings

It happens more than you think. If the thermostat is set to Heat or Fan On, the system will not cool well. Recovery schedules can delay cooling. Smart thermostats may hold energy saver modes that cap output during peak hours. A bad temperature sensor can misread the room by several degrees.

What to check now:

  1. Set the mode to Cool and the fan to Auto.
  2. Lower the setpoint 3 to 5 degrees and wait 10 minutes.
  3. Disable Hold or Eco modes temporarily.
  4. Replace the thermostat batteries if used.
  5. Verify time, day, and schedule are correct.

If the outdoor unit does not start, or you see COOL on the screen but feel warm air at vents, a control issue is likely. It could be a loose low-voltage wire, a tripped float switch due to a clogged drain, or a failed control board. These are fast checks for a trained tech.

Reason 2: Dirty Filter or Blocked Airflow

Airflow is the lifeblood of cooling. A clogged filter, dusty coil, blocked return, or closed supply vents can slash capacity. In Austin and Bastrop, live oak pollen and construction dust clog filters quicker in spring and summer. Low airflow causes longer run times, higher humidity, and even coil freeze-ups that stop cooling fully.

DIY steps:

  1. Inspect your filter. If you cannot see light through it, replace it.
  2. Open at least 80 percent of supply vents. Do not close vents in unused rooms.
  3. Clear return grilles of furniture and pet hair.
  4. Rinse debris from the outdoor coil fins with a gentle garden hose spray.

If cooling returns but is still weak, the indoor coil may need a professional cleaning. A maintenance visit also checks blower speed, static pressure, and duct leaks. Small airflow fixes often deliver the biggest comfort gains.

Reason 3: Low Refrigerant or a Leak

A heat pump with a refrigerant leak will still run but not cool well. You may notice warm air, hissing near the indoor unit, ice on the refrigerant lines, or bubbling at the service valves. Low charge reduces heat transfer and can overheat the compressor. Topping off without finding the leak is a short-term bandage and risks further damage.

What a pro will do:

  1. Measure superheat and subcool to confirm charge.
  2. Perform electronic leak detection and nitrogen pressure testing.
  3. Repair or replace leaking components and evacuate the system to deep vacuum.
  4. Recharge to manufacturer spec and verify performance.

If your system uses R-410A, supply and regulation changes continue to affect costs. A repair vs replace discussion makes sense on older systems. Upgrading to a modern heat pump can improve energy efficiency by up to 30 percent, which helps offset repair costs over time.

Reason 4: Frozen Coils or Iced Refrigerant Lines

Ice is a symptom, not a cause. It points to low airflow, low refrigerant, or control faults. When the indoor coil freezes, airflow stops and vents blow warm or no air. Outdoors, you may see a frosted coil even in summer. Do not chip ice. That damages fins and can puncture tubing.

Immediate actions:

  1. Turn the system off at the thermostat.
  2. Set the fan to On to thaw the indoor coil faster.
  3. Place towels near the air handler for condensate runoff.

After thawing, replace the filter and restart cooling. If ice returns, schedule service. A tech will test static pressure, blower motor amps, and refrigerant levels. Finding the root cause prevents repeat freeze-ups and protects the compressor.

Reason 5: Failing Parts: Capacitors, Fan Motors, or Reversing Valve

If the outdoor fan or compressor hums but does not start, a weak capacitor is likely. If the outdoor fan runs but air is not cool, the compressor may not be running. A stuck reversing valve can leave the system in heat or neutral mode. Short-cycling, clicking relays, or burnt smells hint at electrical failures.

What we check:

  1. Capacitor microfarads against rated value.
  2. Contactor pitting and voltage drop.
  3. Compressor start amp draw and insulation resistance.
  4. Reversing valve solenoid function and temperature differential.

Replacing a capacitor or contactor is a straightforward repair. A reversing valve or compressor issue is more complex. When key parts fail on older units, replacement may save money over a two-summer repair cycle.

Bonus Causes: Duct Leaks, Sizing Errors, and Insulation Gaps

Sometimes the heat pump is fine. The house is not. Leaky ducts in a 130-degree Bastrop attic spill cold air where you do not want it. Return leaks suck hot, dusty attic air into the system. An undersized or oversized unit will not control humidity or cycle properly. Poor attic insulation or radiant heat gain can overwhelm even a healthy system.

Signs to watch:

  1. Large temperature swings between rooms.
  2. Dust streaks at supply registers, pointing to duct leaks.
  3. High humidity even when the system runs constantly.

A load calculation and duct inspection can reveal these silent killers. Fixing ductwork and adding insulation often delivers better comfort than another thermostat tweak.

DIY Checks vs Professional Service

Do these safe checks before calling:

  1. Confirm thermostat mode and setpoint.
  2. Replace the filter and open supply vents.
  3. Rinse outdoor coil fins from the outside in.
  4. Check the breaker and outdoor disconnect.
  5. Inspect the condensate drain. If the pan is full, call a pro.

Call a licensed HVAC tech if you see icing, hear grinding or buzzing, smell burning, or the breaker trips again after a reset. Professional diagnostics catch multi-factor problems like a weak blower and low charge that mimic simple issues. Expect a full system evaluation, not a quick guess.

Repair or Replace: Making the Smart Call

A targeted repair is right when the unit is newer, parts are available, and your bills have been stable. Replace when the compressor is failing, major leaks exist, or your system is over 12 years old and struggles in heat waves. Financing can spread costs. At Parobek, heat pump installs start at $134 per month with approved credit, and we install air-source, geothermal, water-source, and mini-split systems to fit your home.

Pro tip: If you plan to sell in a few years, an efficient heat pump can boost home value and cut carrying costs. Our team will compare SEER2 ratings, comfort features, and warranty terms so you pick with confidence.

The Value of Preventive Maintenance

Regular tune-ups catch small problems before they become breakdowns. Our $55 Heat Pump Check-Up comes with a No-Breakdown Guarantee for 6 months. If the system fails within that window, we come back at no cost to diagnose, give you priority scheduling, and credit the $55 toward the repair. We also donate $10 from each check-up to a local animal shelter, so your maintenance helps the community.

What we check in a tune-up:

  1. Refrigerant performance, superheat, subcool.
  2. Electrical health, capacitors, contactors, safeties.
  3. Airflow, static pressure, blower speed, and coils.
  4. Thermostat calibration and drain performance.

What to Expect When You Call Parobek

We offer a 24-hour live answering service, so you can book next-day service even if you call after hours. For repairs, our $75 Heat Pump Repair Dispatch Charge covers the trip and expert diagnosis. When we do the work, we waive the dispatch charge. You will get upfront pricing and clear options before we start. Most parts are on the truck, so many fixes are same day.

We work on most brands and handle everything from simple capacitor swaps to complex refrigerant leak repairs and reversing valve replacements. If replacement is best, we offer options from ductless mini-splits to variable refrigerant flow systems. Our goal is a right-sized, efficient solution that fits your budget.

Special Offers for Faster, Smarter Cooling

  • Save $100 on Heat Pump Services. Mention this blog and ask for the $100 OFF Heat Pump Services offer.
  • $55 Heat Pump Check-Up with a 6-month No-Breakdown Guarantee. We donate $10 of every check-up to a local animal shelter.
  • $75 Heat Pump Repair Diagnostic. We waive the $75 dispatch charge when we complete the repair.
  • Heat Pump Install Starting at $134 per month with approved credit.

Call (512) 937-1747 or schedule at https://www.parobekplumbing.com/.

What Homeowners Are Saying

"Very professional, Cody Price came and evaluated our system and made the right recommendations for a replacement with a high efficiency heat pump. Very knowledgeable."
–Jose R., Heat Pump Replacement

Frequently Asked Questions

Why is my heat pump blowing warm air in Cool mode?

A stuck reversing valve, low refrigerant, or a thermostat error can cause warm air. Confirm Cool mode and a lower setpoint. If the outdoor unit runs but air is warm, call for service to test the valve and charge.

How long should it take to cool my home by a few degrees?

Most systems drop indoor temperature 1 to 2 degrees per hour, depending on outdoor heat and humidity. If it stalls for over an hour, check filters and vents, then schedule diagnostics for airflow and refrigerant.

Can I reset my heat pump to clear a fault?

Yes. Turn the thermostat Off for 5 minutes, then restore Cool. Flip the outdoor disconnect off and on once. If the breaker trips or you see icing or buzzing, stop and call a licensed tech.

Are refrigerant leaks dangerous or expensive?

Small leaks reduce efficiency and can snowball into compressor damage. A proper fix includes leak find, repair, evacuation, and recharge. Costs vary by location and size of leak. Acting early saves money.

Do mini-splits have the same cooling problems?

They can. Dirty filters, low refrigerant, or control issues affect mini-splits too. The diagnostics are similar, but access and parts differ by brand. Regular cleaning and pro tune-ups keep them reliable.

The Bottom Line

If your heat pump is not cooling, start with settings and airflow, then consider refrigerant and parts. Parobek solves cooling issues across Bastrop, Austin, Elgin, and nearby. We pair fast response with licensed expertise and strong guarantees.

Ready to Get Comfortable Again?

Call (512) 937-1747 or book at https://www.parobekplumbing.com/ to schedule your $55 Heat Pump Check-Up or a $75 diagnostic, both backed by our No-Breakdown Guarantee and waived dispatch with repair. Get cool, stay efficient, and save with Parobek today.

Call now: (512) 937-1747 • Schedule online: https://www.parobekplumbing.com/ • Ask for $100 OFF Heat Pump Services or the $55 Check-Up with 6-month No-Breakdown Guarantee.

About Parobek Plumbing & Air Conditioning

Family owned and local to Bastrop County, Parobek Plumbing & Air Conditioning brings 25+ years of service and 100+ years of combined experience. We back work with a 100% satisfaction guarantee and upfront pricing. Our team holds licenses M-17953 and TACLB136431E. We have been voted Best Plumber and Best Heating and Air Conditioning in Bastrop County for 5 years. Same-day service is often available, and we offer financing, including installs starting at $134 per month.

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