Why Your Heat Pump Isn’t Cooling Your Home
If your heat pump is not cooling, you feel it fast. Muggy rooms, rising humidity, and a thermostat that never seems to hit the setpoint. In this guide, we break down the most common causes and what you can safely do before calling for help. When you need a hand, Yost & Campbell offers 24/7 heat pump repair across Westchester and nearby boroughs.
How a Heat Pump Cools Your Home
A heat pump moves heat, not fuel. In cooling mode, it pulls heat from indoor air and releases it outdoors. That process depends on correct airflow, refrigerant volume, and clean heat transfer surfaces. If any of those break down, comfort drops and energy use rises.
Two hard facts homeowners should know:
- Heat pumps typically last 10 to 15 years. Replacing within that window can boost efficiency and reduce costs.
- Pro maintenance twice a year, in spring and fall, keeps performance steady and helps prevent breakdowns before peak season.
Local note: Westchester summers bring sticky humidity. When a heat pump is underperforming, you will notice damp air and longer run times even when outdoor temps are moderate.
Reason 1: The Thermostat or Controls Are Set Incorrectly
It sounds simple, but wrong settings are a top cause of weak cooling.
Start here:
- Confirm the system is on Cool, not Heat or Auto during shoulder seasons.
- Set the fan to Auto. Fan On can push warm air when the compressor is off.
- Lower the setpoint at least 3 degrees below room temperature and wait a full 10 minutes.
- Check schedules and vacation modes. A smart thermostat may be holding a higher temp.
If the system still does not cool, look for short cycling. That is when the outdoor unit starts and stops quickly. It can be caused by wiring issues, a bad sensor, or low refrigerant. Do not bypass safeties or jump wires. If controls seem erratic or you see short cycling, schedule service. Our technicians can isolate failed sensors, update thermostat firmware, and correct control wiring.
Pro tip: If you recently changed to a hybrid dual fuel setup, make sure the thermostat is configured for heat pump with electric cooling, not conventional AC, and that lockout settings match your system design.
Reason 2: Dirty Filter or Restricted Airflow Indoors
Insufficient airflow is the enemy of cooling. A clogged filter, closed vents, blocked returns, or a dirty indoor coil will starve the system of air. That leads to poor cooling and can even ice the coil.
Do this now:
- Replace or clean the filter. Many homes in our area need a change every 30 to 60 days in summer.
- Open at least 80 percent of supply vents. Closing too many to “push” air elsewhere backfires.
- Clear return grilles. Laundry baskets and furniture are common culprits.
- If you see frost on the indoor coil or lineset, turn the system Off and fan to On for 60 minutes to thaw. Then set fan back to Auto and try cooling again.
If icing returns, the cause may be deeper: a failed blower motor, a collapsed duct, or a dirty evaporator coil you cannot access without a service panel removal. We handle coil cleaning and blower repairs daily. Our Home Comfort Club members get routine cleanings that help prevent these airflow issues before the first hot spell.
Reason 3: Frozen Coils or a Refrigerant Leak
A healthy refrigerant circuit maintains specific pressures and temperatures. When refrigerant is low, the indoor coil can drop below freezing, frost over, and cooling stops.
Warning signs:
- Hissing at the indoor or outdoor unit
- Ice on copper lines or the indoor coil panel
- Warm supply air after 10 to 15 minutes of run time
- Short cycling with rising humidity
Do not attempt to add refrigerant yourself. Modern systems use precise charge levels. Overcharging is as harmful as undercharging. A licensed technician will locate leaks, repair them, and weigh in the correct charge per the manufacturer’s data plate.
Another cause of freezing is a stuck or failed reversing valve. You might notice the unit heating when it should be cooling or refusing to switch modes. That is a professional repair. Yost & Campbell provides 24-hour emergency heat pump repairs when your system quits on a hot night.
Pro fact: Many heat pump manufacturers specify that refrigerant circuits be evacuated to 500 microns during service for moisture removal. That level of precision requires pro tools and training.
Reason 4: Outdoor Unit Problems and Blocked Heat Release
Your outdoor unit must dump the heat pulled from indoors. If it cannot expel that heat, cooling suffers.
Check these items:
- Clear a 2 to 3 foot radius around the condenser. Trim shrubs, pick up leaves, and keep grass clippings away.
- Rinse the coil gently from the inside out with a garden hose. Avoid pressure washers.
- Listen for unusual noises. A noisy fan, rattling grille, or grinding motor points to a failing component.
- Inspect for bent fins and a clogged coil. Dirt forms an insulating blanket that blocks heat transfer.
Electrical issues can also stop the outdoor unit. A blown fuse, a failed contactor, or a swollen capacitor are common failures. If the indoor blower runs but the outdoor unit is silent, cut power at the disconnect and call for service. We stock common parts on our trucks and can often restore cooling in one visit.
Local insight: In tight side yards from Yonkers to the Bronx, condensers sit near fences where lint and cottonwood collect. A spring rinse can add back several degrees of cooling capacity.
Reason 5: An Aging or Mismatched System
Even a well-maintained heat pump reaches the end of its prime. After about 10 to 15 years, compressors lose efficiency, coils corrode, and controls fail more often. If your system is older, not cooling well, and repairs are piling up, it may be time to compare replacement to repair.
What to consider:
- Age and repair history over the last two summers
- Comfort gaps such as hot upstairs rooms or humid first floors
- Utility costs trending up despite same usage
- Proper sizing and duct condition. A system that is too big or too small will struggle.
Modern high-efficiency heat pumps deliver strong cooling and better dehumidification. For cold climate peace of mind, we design hybrid dual fuel systems that pair an air source heat pump with a gas furnace for seamless comfort year-round. Our team can install most heat pumps in less than a day and handle rebate paperwork.
Money saving fact: ConEdison incentives can reduce upfront cost by up to $12,000 on qualifying high efficiency heat pumps. Federal tax credits may also apply. We will review options during your estimate.
Safe DIY Checklist Before You Call
- Set thermostat to Cool and fan to Auto. Lower the setpoint by 3 degrees.
- Replace the air filter and open returns and supply vents.
- Clear 2 to 3 feet around the outdoor unit. Rinse coils gently.
- Look for frost. If present, thaw by turning cooling Off and the fan On for one hour.
- If the outdoor unit does not run, stop and call a pro. Do not open electrical panels.
When you are ready for help, Yost & Campbell offers same day appointments and 24/7 emergency service. Our technicians can diagnose refrigerant leaks, fix short cycling, and get your home cooling again fast.
Special Offer: Save Big on High Efficiency Heat Pumps
Save up to $12,000 with current ConEdison rebates on qualifying heat pump installations. This cannot be combined with other offers. Call 914-668-6461 or schedule online to check eligibility and book your free estimate.
What Homeowners Are Saying
“Yost and Campbell did a wonderful jon installing my hew heat pump.The installers were like artisans at their craft.Punctual, patient and polite.Bravo !”
–Vince P., Heat Pump Installation
“I had 3 systems installed by Yost and Campbell and I could not be happier (one for each floor of my home). The salesman Omar Hernandez was very polite, knowledgeable, and designed a perfect hvac system for my home. He recommended a heat pump system and not only does it perform beyond my expectations, it also has saved me more than half on my utility bills monthly cost.”
–Carlos M., Heat Pump Installation
“Had a great experience. Austin Aviles was excellent and very knowledgeable. Had 2 AC/heat pump units installed… The crew was phenomenal. Neat and professional… They walked me through everything before they left and made sure I knew how to operate the new system. I highly recommend them.”
–Angel T., Heat Pump Installation
Frequently Asked Questions
Why is my heat pump blowing warm air in cooling mode?
Check that the thermostat is set to Cool and fan to Auto. If settings are correct, the reversing valve or low refrigerant may be the cause. Call for service if it persists.
How often should I change my heat pump filter in summer?
Every 30 to 60 days for most homes, sooner with pets or construction dust. A clean filter protects the coil and keeps cooling performance steady.
Is it safe to run my heat pump if the indoor coil is frozen?
No. Turn cooling Off and the fan On to thaw for about an hour. Running while iced can damage the compressor. Schedule service to correct the root cause.
When should I repair vs. replace a heat pump that is not cooling?
If your unit is 10 to 15 years old with rising repair costs or poor comfort, compare replacement. New systems cool better and may qualify for rebates and tax credits.
Do I need maintenance even if my system seems fine?
Yes. Twice yearly service in spring and fall keeps efficiency high, catches small issues early, and helps avoid breakdowns during peak heat.
Conclusion
A heat pump that is not cooling usually comes down to controls, airflow, refrigerant, the outdoor unit, or system age. Start with the safe checklist above, then call a pro if the problem remains. For Westchester homeowners searching for help with a heat pump not cooling, Yost & Campbell is ready day or night.
Schedule Service Today
Call 914-668-6461 or book online. Ask about current ConEdison rebates up to $12,000 on qualifying heat pumps and our Home Comfort Club for year round protection.
About Yost & Campbell
Since 1939, Yost & Campbell has kept Westchester and the surrounding counties comfortable with certified technicians, 24/7 emergency service, and honest, upfront work. We install most heat pumps in less than a day, maintain all brands, and stand behind our repairs. We are affiliated with ConEdison, hold local licensing, and have earned awards such as Angi’s Super Service Award. Ask about our Home Comfort Club and EASE Comfort program for ongoing care and value.
