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November 24, 2025

Leander, TX Heat Pump Not Cooling? 5 Common HVAC Causes

Estimated Read Time: 9 minutes

When a heat pump not cooling your home collides with an Austin summer, comfort drops fast and energy bills rise. The good news: most cooling failures trace back to a few common issues you can check quickly. Below are the top five reasons your heat pump struggles, what you can safely do now, and when it is smart to call SALT for a fast, lasting fix. SALT+ members get priority scheduling.

How Heat Pumps Cool and Why Small Issues Create Big Discomfort

A heat pump moves heat out of your home in summer and into your home in winter. It does this with refrigerant, coils, a compressor, and a reversing valve. When any link in that chain is weak, you feel it room by room. In Austin’s long cooling season, even a small airflow or refrigerant issue compounds quickly.

Two local realities make troubleshooting urgent:

  1. Austin’s average summer highs sit in the 90s for months, which widens the gap your system must overcome and exposes weak components fast.
  2. Typical lifespan ranges 10 to 15 years. Past year 10, efficiency and reliability decline, and maintenance becomes more critical to avoid costly breakdowns.

If your thermostat is set right but your vents push lukewarm air, start with airflow checks. If the outdoor unit is quiet when it should run, you may have an electrical or safety lockout. The sections below break down the five most common causes with steps you can take today.

Reason 1: Thermostat or Settings Are Working Against You

Simple settings cause more no-cooling calls than you might expect. A thermostat in Heat mode or Auto changeover with a too-narrow deadband can bounce the system and reduce cooling. Incorrect schedules and sensor placement also lead to false readings.

What to check now:

  1. Confirm Cool mode and set a target at least 3 degrees below room temperature.
  2. Set fan to Auto. On can circulate warm attic or crawlspace air.
  3. Review schedules and hold settings. Disable vacation modes.
  4. If you have a smart thermostat, check Wi‑Fi, firmware, and any eco features that limit runtime during peak pricing windows.

When to call:

  • Short cycling, blank screens, or miswiring after a DIY upgrade need a diagnostic. SALT can verify low-voltage signals, staging, and compatibility with heat pump controls.

Reason 2: Dirty Filters or Blocked Airflow Starve the System

Restricted airflow is the fastest way to turn a solid heat pump into a poor performer. A clogged filter, closed supply registers, or a matted indoor coil prevents heat transfer. That forces longer run times, higher bills, and sometimes a frozen coil.

What to check now:

  1. Replace or wash the air filter. In Austin’s cedar and oak seasons, monthly checks are smart.
  2. Open at least 80 percent of supply registers. Do not block returns with furniture or curtains.
  3. Inspect the indoor unit for ice. If you see frost, turn the system Off, set the fan to On for 60 minutes to thaw, then restore to Cool and Auto.

When to call:

  • Ice returns quickly, or airflow still feels weak. SALT performs static pressure tests, inspects duct leaks, and cleans coils safely to restore system capacity.

Reason 3: Low Refrigerant or a Leak Reduces Cooling Capacity

Your heat pump relies on precise refrigerant charge. Low charge means the system cannot absorb and move enough heat. You may notice long cycles, warm supply air, bubbling or hissing at lines, or ice at the evaporator.

What to check now:

  1. Look for oily residue on refrigerant lines. Oil traces often mark leak sites.
  2. Listen for new hissing near the indoor coil or outdoor unit.
  3. Avoid running the unit for hours if ice is present. You risk compressor damage.

When to call:

  • Only licensed technicians should measure superheat, subcooling, and pressures, then find and fix leaks. SALT performs EPA-compliant recovery, weighs in charge, and validates performance so you get safe, efficient cooling.

Reason 4: Outdoor Unit Issues, From Debris to Failing Fan Motors

The outdoor unit must release heat. If it is choked with cottonwood, grass clippings, or lint, head pressure rises and cooling collapses. A failing condenser fan or contactor can also stop heat rejection entirely.

What to check now:

  1. Clear vegetation within 2 feet of the cabinet. Gently rinse coils from the inside out if accessible and safe.
  2. Make sure the top fan spins when the system runs. If it hums or starts then stops, shut the system off.
  3. Verify the outdoor breaker and service disconnect are on. Reset a tripped breaker once only.

When to call:

  • Repeated breaker trips, burnt smells, or a non-spinning fan point to electrical or motor problems. SALT checks voltage, capacitors, contactors, and motor windings and addresses related issues so the repair holds up through peak heat.

Reason 5: Reversing Valve or Defrost Control Problems

A stuck reversing valve can trap the unit in an in-between state where it neither cools nor heats well. Defrost control faults can also confuse the system and interrupt cooling cycles, especially after rainy spring cold snaps.

Signs to watch:

  • Lukewarm air regardless of thermostat setting.
  • Outdoor unit switches modes unexpectedly.
  • Frequent clicking without steady operation.

What to do now:

  1. Power cycle at the breaker for 5 minutes to reset control boards.
  2. Confirm thermostat is calling for cool and the outdoor unit receives the signal.

When to call:

  • Reversing valves, defrost boards, sensors, and solenoids are specialty parts. SALT diagnoses control logic, verifies coil temperatures, and replaces components to restore reliable cooling.

Other Austin-Specific Culprits You Should Not Ignore

Duct leaks: Many Greater Austin homes lose 20 to 30 percent of conditioned air through unsealed or uninsulated ducts in attics. That feels like weak cooling at the register even when the heat pump is fine.

Attic temps: Summer attic temperatures commonly exceed 120 degrees. That punishes air handlers located in the attic and exposes marginal parts.

Aging systems: Past 10 to 15 years, efficiency falls and repairs stack up. Modern heat pumps deliver higher efficiency and quieter operation, and they remove the need for combustible fuels.

What SALT checks on a no-cooling call:

  1. Airflow and static pressure across the system.
  2. Refrigerant levels and temperature splits.
  3. Electrical voltages and control signals.
  4. Installation issues, tampering, and safety devices.
  5. Signs of mold or contamination that affect performance and air quality.

DIY vs Pro: A Simple Decision Tree

Try these homeowner-safe steps first:

  1. Set thermostat to Cool and Auto. Replace the filter.
  2. Open registers and clear the outdoor unit.
  3. Thaw ice by running Fan only for an hour, then test cooling.
  4. Reset breakers once. Note any error codes on smart stats.

Call a professional if you notice any of the following:

  • Ice returns or supply air stays warm after basic checks.
  • Breakers trip, the outdoor fan will not run, or you hear loud metallic sounds.
  • Visible oil on lines or coils, or a strong refrigerant smell.
  • System is older than 10 years and repairs are becoming frequent.

Repair, Replace, or Maintain: Choosing the Best Path

Repair is smart when the unit is newer, the issue is isolated, and energy bills are normal. Typical examples include a failed capacitor, a clogged drain, or a dirty coil.

Replacement is smart when:

  1. The unit is 10 to 15 years old and major components are failing.
  2. You face repeated refrigerant leaks or obsolete refrigerants.
  3. Electricity bills are climbing and comfort remains poor.

Maintenance is always smart. SALT recommends at least one professional tune-up a year to catch problems early, keep efficiency high, and protect your warranty. Our SALT+ membership provides regular maintenance checks, priority service, and member pricing to reduce surprise costs and extend system life.

Why Austin Homeowners Choose SALT for Heat Pump Cooling Problems

  • Local since 1984 with same day service across Austin, Round Rock, Georgetown, Cedar Park, Leander, Pflugerville, Kyle, Hutto, Del Valle, and Belton.
  • Licensed, trained HVAC technicians who handle installation, repair, and replacement.
  • Full-service diagnostics that address root causes, not just symptoms, for longer-lasting fixes.
  • Modern, energy-efficient replacement options that are whisper-quiet and reduce utility costs.
  • SALT+ membership for priority scheduling, exclusive discounts, and scheduled tune-ups that prevent most breakdowns before they start.

Special Offer: Member Savings That Keep You Cool

Join SALT+ and save up to 15% on heat pump repairs and 5% on new heat pump installations, plus get priority scheduling and regular maintenance checks. Perfect for Austin summers and Hill Country allergy season. Call (512) 559-4206 or visit https://callsalt.com/ to enroll today.

What Homeowners Are Saying

"David is very knowledgeable, thorough, and professional. He explained the heat pump mechanism and operation very clearly. I enjoyed having him in my home and would trust him to resolve any future issues we might have." –Austin homeowner
"So far, quick and efficient. Chris came out to quote a mini- split installation. All other major HVAC companies had no interest in in installing a new customer purchased unit. Price was supplied the same day and was within my estimate." –Central Texas homeowner

Frequently Asked Questions

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

Incorrect thermostat mode, a clogged filter, low refrigerant, or a dirty outdoor coil are common causes. Start with settings and a fresh filter, then call SALT to check charge, airflow, and electrical.

Can low refrigerant damage my heat pump?

Yes. Low charge can overheat the compressor and cause ice buildup. Shut the system off if you see frost and schedule service. Only licensed techs should test pressures and add refrigerant.

How often should I maintain my heat pump in Austin?

Schedule at least one professional tune-up per year. Heavy summer usage makes spring maintenance smart. SALT+ membership includes regular checks and priority service.

When is replacement smarter than repair?

If your system is 10 to 15 years old, has major component failures, or needs frequent refrigerant top-offs, replacement can lower bills, reduce repairs, and improve comfort.

What do SALT technicians check on a no-cooling visit?

We check airflow, refrigerant levels, electrical voltages, installation issues, safety devices, and signs of contamination. The goal is a reliable fix that lasts through peak heat.

The Bottom Line

If your heat pump not cooling your home is the challenge, start with settings and airflow, then bring in a pro for refrigerant or control issues. For expert help in Austin and nearby cities, call SALT Plumbing Air & Electric at (512) 559-4206 or schedule at https://callsalt.com/. Ask about SALT+ to save up to 15% on repairs and 5% on installs.

Ready for Fast Relief?

  • Call now: (512) 559-4206
  • Schedule online: https://callsalt.com/
  • Save today with SALT+: Up to 15% off repairs and 5% off installations

Get same day service across Greater Austin. We will diagnose, fix, and stand behind the work so your home stays comfortable all summer.

About SALT Plumbing Air & Electric

Family owned and serving Greater Austin since 1984, SALT provides HVAC, plumbing, and electrical with licensed, trained technicians and same day service. We stand behind our work with strong guarantees and local awards, including multiple Best in Austin honors. Ask about SALT+ membership for priority service, regular maintenance, and member pricing. One trusted team for total home care, from Round Rock to Kyle.

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