My Heat Pump Isn't Heating: Common Issues and Quick Fixes

Why Is My House So Cold?

When your heat pump not heating house properly, the problem usually falls into one of a few common categories. Here's what to check first:

Quick Troubleshooting Checklist:

• Thermostat Settings - Verify it's set to "Heat" mode and the temperature is higher than current room temp
• Air Filter - A clogged filter blocks airflow and can prevent heating
• Circuit Breakers - Check if the breaker for your heat pump has tripped
• Outdoor Unit - Clear away snow, ice, leaves, or debris blocking the unit
• Defrost Mode - Your heat pump may temporarily blow cool air while melting ice buildup
• Extreme Cold - Heat pumps struggle below freezing and may need auxiliary heat

There's nothing worse than walking into a cold home in Wakulla, Leon, or Franklin County when your heat pump should be keeping you warm. Heat pumps work by transferring heat from outside air into your home, even when it's cold out. They're efficient systems that both heat and cool your home, but when something goes wrong with the heating cycle, the issue could be as simple as a wrong thermostat setting or as complex as a refrigerant leak.

For expert heat pump diagnostics and repair throughout the Big Bend area, visit our HVAC services page or contact Keith Key Heating & Air to schedule service today.

Most heat pump heating problems fall into two categories: simple fixes you can handle yourself, and mechanical failures that need a trained technician. Understanding the difference can save you time, money, and frustration. In this guide, we'll walk through both scenarios so you know exactly what to check and when to call for help.

A heat pump is a marvel of modern HVAC technology, designed to keep your home comfortable year-round. Unlike a furnace that generates heat by burning fuel, a heat pump simply moves heat. In the winter, it extracts heat from the outside air, even when temperatures are low, and transfers it indoors. This process makes them incredibly energy-efficient. Your residential heat pump works by both heating and cooling your home throughout the changing seasons. This system comprises an outdoor unit, an indoor unit, and your thermostat, all working in harmony to keep your family cozy.

First Steps: Simple DIY Checks for Your Heat Pump

Before you panic and call for service, performing a few quick and easy checks can often solve the problem and restore warmth to your home. Many heat pump issues are surprisingly simple to resolve, saving you time and hassle.

Check Your Thermostat Settings

One of the most frequent culprits behind a heat pump not heating house is an incorrect thermostat setting. It might sound obvious, but it's easy for settings to get accidentally changed.

First, ensure your thermostat is set to "Heat" mode, not "Cool." If it's set to cooling mode, it will blow cold air, which is definitely not what we want on a chilly day.

Next, check the fan setting. It should be on "Auto," not "On." If the fan is set to "On," it will run continuously, blowing air even when the heat pump isn't actively in its heating cycle. This can make the air feel cool, deceiving you into thinking there's a problem. When set to "Auto," the fan only runs when the system is actively heating or cooling.

Finally, confirm your desired temperature is set higher than the current room temperature. If your home is 68°F, and you've set the thermostat to 65°F, your heat pump won't turn on. We recommend setting the thermostat no more than 4 degrees above your current room temperature. If your home still feels cold, you can try bumping it up another 5 degrees. If your heat pump has an "Emergency Heat" or "Auxiliary Heat" option, you can try switching to that temporarily to see if warm air comes out. This can help us determine if the issue is with the heat pump itself or its ability to extract heat from outside.

It's also worth checking if your programmable thermostat is set to the correct time for heating. A faulty or uncalibrated thermostat can also cause issues, failing to signal the heat pump to switch modes or turn on. Consulting your thermostat's manual can offer guidance on recalibration if you suspect this is the case.

Inspect for Airflow Obstructions

Your heat pump relies on unobstructed airflow to operate efficiently. Any blockage can severely impact its ability to heat your home.

The most common airflow obstruction is a dirty air filter. A clogged air filter restricts airflow, forcing your heat pump to work harder and reducing its efficiency. This can lead to your heat pump not sufficiently heating your home or blowing cool air because it can't circulate enough warm air. We recommend checking and cleaning or replacing your air filters regularly to ensure proper airflow, typically every 1-3 months, depending on your home environment and filter type. A dirty air filter blocks airflow to the air handler, impacting performance.

Beyond the indoor filter, the outdoor unit also needs clear space to breathe. Leaves, dirt, grass clippings, and even snow and ice can accumulate around and inside the outdoor unit, hindering its performance. We advise regularly cleaning the outdoor unit and removing any obstructions to ensure proper heat transfer. Make sure there's at least two feet of clear space around the unit, and trim back any nearby vegetation.

Reset the Power

Sometimes, your heat pump just needs a good old-fashioned reboot. Electrical issues can temporarily halt its operation.

Check your home's main electrical panel for tripped circuit breakers. Heat pumps typically have two breakers: one for the indoor unit (air handler) and one for the outdoor unit (compressor). If either of these has tripped, simply flip it back to the "On" position. Safety first: if a breaker repeatedly trips, it indicates a more serious electrical issue that requires professional attention.

Additionally, verify that the power switch for your indoor unit is in the "On" position. This switch often looks like a regular light switch and is located near your indoor air handler. Similarly, check for an outdoor disconnect switch, usually located in a small box near the outdoor unit, and ensure it's in the "On" position. A disconnected power switch on the outdoor unit or a blown fuse can stop the unit from running entirely.

Understanding Why Your Heat Pump Blows Cold Air

It can be quite alarming to feel cold air coming from your vents when you expect warmth. However, sometimes a heat pump blowing cool air is part of its normal operation. Understanding these cycles can save you from a needless service call and a lot of worry.

Is It Just in Defrost Mode?

One common reason your heat pump might blow cool air is if it's in defrost mode. Heat pumps have a defrosting cycle to remove frost or ice buildup on the outdoor coils. This is a normal and necessary function, especially in colder temperatures.

During the defrost cycle, your heat pump temporarily reverses its operation, essentially acting like an air conditioner for a short period to melt the ice on the outdoor coil. This means it draws heat from inside your home and sends it to the outdoor unit. As a result, the air blowing from your indoor vents will feel cool for a few minutes. You might also notice steam rising from the outdoor unit (this is just water vapor, not smoke!) or hear a loud whooshing sound, similar to air brakes on a bus. These are all normal signs of a heat pump in defrost mode.

If the defrost cycle lasts longer than a few minutes or if the heat pump continues to blow cold air after what seems like a reasonable time, there may be an issue with the defrost system itself. Most defrost cycles are designed to run for a set duration, often between 10 to 20 minutes, or until the coil is clear of ice. A puddle of water near the outdoor unit after a cycle is a good indicator that it successfully defrosted.

The Impact of Extreme Cold Weather

Heat pumps are incredibly efficient, but their performance can be affected by extreme cold. While they can extract heat from surprisingly low temperatures, their efficiency decreases as the outdoor temperature drops below freezing.

When temperatures fall significantly, your heat pump may struggle to gather enough heat from the outside air to comfortably warm your home. This is when your supplemental heat source, often called "auxiliary heat" or "emergency heat," kicks in. Most heat pumps in our area are equipped with electric resistance heating elements or, in some cases, a gas or oil furnace, to supplement the heat pump's output during colder weather.

If your heat pump is running near-constantly in very cold weather, it might not be a malfunction. Heat pumps are designed to work much more gradually than a furnace, so they may run for longer cycles without necessarily indicating a problem. However, if your home isn't reaching the desired temperature, your supplemental heat might not be engaging or could be insufficient. Relying solely on electric resistance heating as a supplemental source can lead to a much higher electric bill, so it's important to ensure your heat pump is operating optimally before solely depending on auxiliary heat.

Common Mechanical Issues Causing a Heat Pump Not Heating House

If the simple checks don't work and it's not a normal operational cycle, your system may have a mechanical failure that requires professional attention. These issues are typically beyond DIY fixes and should always be handled by a certified HVAC technician.

Signs of a Refrigerant Leak

Refrigerant is the lifeblood of your heat pump, transferring heat between the indoor and outdoor units. If your heat pump is experiencing low refrigerant levels, it's almost always due to a leak. Refrigerant operates in a closed loop, so it should never diminish unless there's a breach in the system.

Signs of a refrigerant leak can include:

• Reduced Heating Capacity: This is the most obvious symptom. If your heat pump isn't blowing warm air or can't keep your home warm, low refrigerant is a likely cause.
• Hissing or Bubbling Sounds: You might hear these noises coming from the outdoor unit or near the refrigerant lines if there's a leak.
• Frozen Evaporator Coil: Low refrigerant pressure can cause the evaporator coil (the indoor coil) to become excessively cold, leading to ice buildup. A frozen outdoor coil can also be a sign of low refrigerant charge.
• Oily Residue: Refrigerant contains oil, so you might spot an oily film or residue around the refrigerant lines or components where the leak is occurring.

A refrigerant leak is a serious issue that requires professional attention. Trying to fix it yourself can be very dangerous. A professional technician will be able to find the leak, repair it, and recharge the refrigerant to the correct levels.

A Malfunctioning Reversing Valve

The reversing valve is a critical component that truly differentiates a heat pump from a conventional air conditioner. It's responsible for switching the direction of refrigerant flow, allowing your system to either heat or cool your home.

If your heat pump works perfectly in cooling mode but fails to heat, a malfunctioning reversing valve is a likely culprit. When this valve gets stuck or fails, the heat pump can't properly switch into heating mode. You might hear clicking noises as the system tries to activate the valve, but the refrigerant flow isn't redirected correctly.

A failing reversing valve is a complex mechanical issue that requires professional diagnosis and repair. We don't recommend attempting to fix this yourself, as it involves specialized knowledge of refrigerant systems and internal components.

When to Call a Professional for Your Heat Pump

Knowing when to tackle a problem yourself and when to call for expert help is key to avoiding further damage and ensuring your safety. While we encourage homeowners to perform basic troubleshooting, there are clear lines where professional expertise becomes essential.

DIY Fixes vs. Professional Repair for a heat pump not heating house

Here’s a quick guide on what you can typically handle and when it’s time to call in the pros:

DIY Tasks (Safe for Homeowners):

• Checking and adjusting thermostat settings.
• Replacing dirty air filters.
• Clearing away debris, snow, or ice from the outdoor unit.
• Resetting tripped circuit breakers (once or twice).
• Checking that power switches (indoor and outdoor) are "On."

Tasks Requiring a Professional (Call Us!):

• Repeatedly Tripping Breakers: This indicates an electrical fault.
• Refrigerant Leaks: Handling refrigerant requires specialized tools and is not a DIY job. A professional technician is needed to locate and repair a refrigerant leak.
• Malfunctioning Reversing Valve: This is an internal component that needs expert diagnosis and replacement.
• Unusual Noises: Grinding, screeching, thumping, or loud banging sounds often point to damaged internal parts like motors or fan blades. If you hear strange noises, turn off the unit and call us.
• Frozen Coils (Persistent): If your outdoor unit is constantly freezing over, even after defrost cycles, or your indoor coil is iced, it could be a refrigerant issue, airflow problem, or defrost system malfunction.
• System Not Turning On At All: After checking basic power, this suggests a deeper electrical or component failure.
• Weak Airflow Even with a Clean Filter: Could indicate ductwork issues, a failing blower motor, or other internal problems.

We always say, when in doubt about heat pump issues, contact a professional HVAC company. Our family-owned and operated business has been dedicated to delivering honest, reliable, and compassionate HVAC service in Wakulla, Leon, and Franklin Counties since 1991. We take pride in exceeding customer expectations with strong work ethics and expert care.

How Regular Maintenance Prevents a heat pump not heating house

The best way to avoid a heat pump not heating house emergency is through regular, preventative maintenance. Think of it like a routine check-up for your car – it helps keep everything running smoothly and prevents minor issues from becoming major, costly repairs.

Regular heat pump maintenance can help the system run more efficiently and potentially increase its lifespan. We recommend scheduling heat pump service visits each fall and spring. During these tune-ups, our technicians will:

• Clean Coils: Keep indoor and outdoor coils free of dirt and debris to ensure optimal heat transfer.
• Check Refrigerant Levels: Verify proper refrigerant charge and inspect for any signs of leaks.
• Inspect Electrical Components: Ensure all wiring, connections, and capacitors are in good working order.
• Test Thermostat: Confirm accurate temperature readings and proper communication with the heat pump.
• Lubricate Moving Parts: Reduce friction and wear on motors and fans.
• Inspect Airflow: Check filters, ductwork, and blower components for obstructions or issues.

This proactive approach preserves efficiency, extends the lifespan of your unit, and can even help maintain your warranty. Many manufacturers require regular maintenance to keep your warranty valid. By catching small problems early, we can prevent the vast majority of repair calls and replacements, ensuring your home stays warm and comfortable all winter long.

Frequently Asked Questions about Heat Pump Heating

We hear a lot of questions about heat pump performance, especially when the weather turns cold. Here are some of the most common ones.

Why does my heat pump blow air that feels cool, not hot?

This is one of the most common misconceptions about heat pumps! Unlike furnaces, which produce hot air (often 120-140°F), heat pumps deliver a steady stream of warm air, typically between 85 and 93 degrees Fahrenheit.

The trick is our body temperature. Our average body temperature is 98.6 degrees Fahrenheit. So, when air that's 85-93°F blows across your skin, it can actually feel cool in comparison, even though it's effectively warming your home. Heat pumps are designed to work much more gradually than a furnace, providing consistent, gentle warmth rather than blasts of super-hot air. If your heat pump is blowing air in this temperature range, it's likely operating normally.

How often should I change my heat pump's air filter?

For optimal performance and air quality, we recommend changing standard HVAC air filters every 1-3 months. However, this can vary based on several factors:

• Filter Type: Some higher-efficiency filters can last longer.
• Home Environment: If you have pets, allergy sufferers, or a lot of dust in your home, you'll need to change them more frequently.
• Usage: During peak heating or cooling seasons when your system runs more often, filters will get dirty faster.

Regularly changing your air filter is one of the simplest and most important maintenance tasks you can do. It ensures proper airflow, preserves efficiency, and helps prevent larger issues like frozen coils.

What should I do if my outdoor unit is completely covered in ice?

While some light frost on your outdoor unit is normal, especially in colder temperatures as part of the defrost cycle, a unit completely encased in thick ice is a sign of a problem.

If your outdoor unit is covered in excessive ice, it could indicate:

• A Defrost Cycle Problem: The defrost mechanism might not be activating or functioning correctly.
• Airflow Issues: Restricted airflow around the unit (e.g., from debris or vegetation) can contribute to freezing.
• Low Refrigerant: As we discussed, low refrigerant can cause coils to get too cold and accumulate ice.

What to do:

1. Turn Off the Heat Pump: Switch your thermostat to "Off" or "Emergency Heat" to prevent further damage.
2. Gently Remove Ice: You can try to gently melt the ice with a hose providing warm (not hot!) water. Never use sharp objects to chip away ice, as this can damage the delicate coils.
3. Inspect for Obstructions: Once the ice is gone, check around the unit for any debris or blockages.
4. Call a Professional: If the unit repeatedly freezes over, if you can't remove the ice safely, or if your heat pump isn't heating after the ice clears, it's time to call us. Excessive ice buildup on the outdoor unit is an issue that should be addressed by a professional technician. We can diagnose the underlying cause, whether it's a defrost issue, low refrigerant, or something else.

Get Your Heat Back with Expert Help

Troubleshooting a heat pump can be straightforward for simple issues like thermostat settings or dirty filters. However, problems like refrigerant leaks or a faulty reversing valve require the expertise of a certified technician. Regular maintenance is the best way to prevent unexpected breakdowns and ensure your system runs efficiently all winter.

For reliable, honest service in Wakulla, Leon, and Franklin Counties, trust the experts at Keith Key Heating & Air. If your heat pump still isn't working, contact us for professional heat pump services from our locations in Crawfordville, Tallahassee, Sopchoppy, and Woodville, FL.