Quick Answer
If your heat pump is running but only blowing cool or lukewarm air during a heating call, the most likely causes are a stuck reversing valve, a low refrigerant charge, a failed defrost control board, an iced outdoor coil, failed auxiliary heat strips, a tripped breaker, or a bad thermostat. Most of these are repairable the same day. The safest first move is to switch the thermostat to emergency heat (if your system has it) so the home stays warm, then call Top Notch Air Conditioning & Heating at (863) 875-5500 for a $99 diagnostic. We serve all of Bartow and Polk County from our Winter Haven headquarters, about 15 miles north. This guide walks through every common cause, what a technician checks, what repairs cost, and when repair makes more sense than replacement.
Why a Heat Pump Not Heating Is a Bartow-Specific Concern
Heat pumps are the most common heating system in Central Florida because the same equipment cools the home for nine months out of the year and heats it during the short winter stretch. In Bartow, the heating season is brief but real. Overnight lows from December through February routinely drop into the 40s, and cold fronts pushing through Polk County can briefly pull temperatures into the 30s. When that happens, a heat pump that worked fine in October is suddenly the only thing standing between your family and a cold house.
Unlike a gas furnace, a heat pump does not generate heat by burning fuel. It moves heat from the outdoor air into the home by reversing the refrigerant cycle that runs your air conditioning. That means the heating function depends on a component called the reversing valve, a functioning defrost cycle, an adequate refrigerant charge, and electric auxiliary heat strips as backup. When any one of those fails, the system may run constantly without ever warming the house, or it may blow cold air outright. Homeowners in downtown Bartow, the Northeast Bartow Residential District, and the Bartow historic district often call us thinking the system is broken in cooling mode, when in fact the heat pump is running but stuck in the wrong cycle.
Top Notch Air Conditioning & Heating has served Polk County since 2012. We are a Carrier Factory Authorized Dealer based at 164 Spirit Lake Rd in Winter Haven, roughly 15 miles from downtown Bartow. Because heat pump heating failures cluster around cold snaps, our phones ring heaviest on the first cold morning of the season. Understanding what is actually wrong before you call helps you make a faster, cheaper decision. For local service details, see our page on heating repair in Bartow, FL.
The 7 Most Common Causes of a Heat Pump Not Heating
Heat pump heating failures almost always trace back to one of seven problems. Some are simple and inexpensive to fix, while others require more diagnosis and parts. Here is what each one looks like from inside the house.
1. Stuck reversing valve
The reversing valve is the component that literally reverses the flow of refrigerant so the heat pump can switch between cooling and heating. It is a pilot-operated brass valve on the outdoor unit controlled by a solenoid coil. If the solenoid fails, the valve gets stuck mechanically, or the control board stops sending voltage to it, the heat pump stays in cooling mode. The indoor fan runs, the compressor runs, but you feel cool air from the supply vents because the system is still rejecting heat outdoors instead of bringing it indoors. A stuck reversing valve is the single most common reason a Bartow homeowner calls us saying "my heat pump is blowing cold air."
2. Low refrigerant charge
A heat pump depends on the correct refrigerant charge to absorb heat from outdoor air, even when that air is only 45 degrees. When the charge is low, the outdoor coil runs too cold, frost builds up faster than the defrost cycle can clear it, and the system cannot extract enough heat to warm the home. A low charge always indicates a leak somewhere in the system. Topping off the refrigerant without finding and repairing the leak is a temporary fix that will repeat. Low charge also strains the compressor and can lead to early failure if left unaddressed.
3. Faulty defrost control or defrost board
In heating mode, the outdoor coil runs below freezing and accumulates frost. The heat pump periodically switches to a defrost cycle, briefly running in cooling mode and turning on the auxiliary heat strips indoors so the home does not blow cold air during the cycle. The defrost control board manages this timing and temperature sensing. If the defrost board fails, the system may never enter defrost, allowing the outdoor coil to freeze into a solid block of ice. Once iced over, the heat pump cannot absorb heat from the air and heating output drops to near zero. A failed defrost sensor or thermistor produces the same result.
4. Iced outdoor coil
A sheet of solid ice across the outdoor coil can be the symptom of a defrost failure, a low charge, poor airflow across the coil, or a combination. Bartow homes with outdoor units tucked under shrubbery, behind fences, or in tight side yards often see restricted airflow that accelerates frost buildup. Once the coil is iced, the heat pump cannot heat regardless of what the thermostat calls for. The fix is to melt the ice safely (never chip it with a tool, you will damage the coil fins), identify the underlying cause, and correct it before restarting in heat mode.
5. Failed auxiliary heat strips
Electric auxiliary heat strips inside the air handler provide backup heat during defrost cycles and during very cold weather when the heat pump alone cannot keep up. In Florida, many homes have 5 to 10 kW of strip heat. If the strips fail, the sequencer (the relay that stages them on) fails, or a high-limit switch trips, you lose your backup heat. The heat pump may still run but cannot warm the house adequately during the coldest mornings, and the defrost cycle blows cold air because there is no strip heat to cover the gap.
6. Tripped breaker or electrical issue
A heat pump has two separate circuits: one for the outdoor unit and one for the indoor air handler (which includes the auxiliary heat strips). If the outdoor breaker trips, the heat pump cannot run at all. If the indoor breaker trips, the blower and heat strips are dead. Breakers trip for a reason, including a shorted heat strip, a failing compressor, a loose connection, or a surge. Resetting a tripped breaker once is reasonable, but if it trips again, the system needs a professional diagnosis. Repeatedly resetting a tripped breaker risks an electrical fire.
7. Bad thermostat or wiring
The thermostat tells the reversing valve what to do. A thermostat that is misconfigured, has dead batteries, has a failed heat-anticipator, or has a loose wire on the O or B terminal can keep the system stuck in cooling mode or prevent the reversing valve from switching. Smart thermostats that were installed incorrectly are a frequent culprit. A homeowner near the Northeast Bartow Residential District recently called us with no heat, and the cause turned out to be a thermostat that had lost its C-wire connection after a power outage reset it to factory defaults.
Causes, Symptoms, and Typical Repair Costs
The table below maps each common cause to the symptom you will notice indoors and the typical repair cost in the Bartow area. Use it as a planning guide. Every repair begins with a $99 diagnostic visit to confirm the actual failure before any work is quoted.
| Cause | Symptom you notice | Typical repair cost (installed) |
|---|---|---|
| Stuck reversing valve | System runs but blows cool air in heat mode | $450-$900 |
| Low refrigerant charge (with leak repair) | Lukewarm air, outdoor coil frosts heavily | $250-$700 |
| Failed defrost control board | Outdoor coil ices over, heat output drops | $300-$650 |
| Iced outdoor coil (clean and correct cause) | No heat, thick ice on outdoor fins | $150-$500 |
| Failed auxiliary heat strips | Cold air during defrost, home will not warm on cold nights | $250-$600 |
| Tripped breaker or electrical fault | Outdoor or indoor unit will not run | $150-$450 |
| Bad thermostat or wiring | System stuck in cooling, or will not switch to heat | $150-$400 |
Pricing reflects Bartow and Polk County market rates as of 2026. Your exact cost depends on equipment make, model, and parts availability. Call (863) 875-5500 to schedule a diagnostic and receive a written quote before any work begins.
Heat Pump Repair vs Electric Furnace Repair: Cost Comparison
Many Bartow homes use either a heat pump or an electric furnace (electric strip heat only, no refrigerant cycle). The two systems heat differently and fail differently. If you are weighing a repair on an older system, the comparison below helps you understand what each path typically costs and what you get for your money.
| Repair or service | Heat pump (typical cost) | Electric furnace (typical cost) | What it includes |
|---|---|---|---|
| Diagnostic visit | $99 | $99 | Full failure identification, written quote |
| Most common heating repair | $450-$900 (reversing valve) | $250-$600 (heat strip or sequencer) | Part replacement plus labor, system test |
| Refrigerant leak repair and recharge | $250-$700 | N/A (no refrigerant circuit) | Leak detection, repair, recharge to spec |
| Defrost board replacement | $300-$650 | N/A | New board, sensor check, defrost cycle test |
| Annual maintenance visit | $129-$199 | $99-$149 | Inspection, cleaning, electrical checks |
| Full system replacement | $5,500-$9,500 | $3,000-$5,500 | New equipment, includes labor and standard warranty |
| Operating cost to heat (per winter) | Lower (moves heat, 2-3x efficiency) | Higher (resistance heat, 1x efficiency) | Heat pumps use less electricity for the same heat output |
The tradeoff is straightforward: a heat pump costs more to repair and replace, but it costs less to run because it moves heat rather than generating it with resistance elements. An electric furnace is cheaper up front and simpler to service, but it costs more to operate over a full winter. For most Bartow homes, a heat pump is the better long-term value because it handles both cooling and heating in one efficient system. For more on heat pump service, see our heat pump repair page.
Diagnosis: What a Technician Actually Checks
When Top Notch Air arrives at your Bartow home, the diagnosis follows a logical sequence rather than guesswork. The goal is to confirm the exact failure before any parts are quoted, so you are not paying for a component that was not the problem. Here is what a typical heating-failure diagnostic includes:
- Thermostat and wiring check. The technician verifies the thermostat is calling for heat, confirms the correct voltage on the O and B terminals, and checks for loose or corroded wires. A thermostat that is misconfigured or has lost its settings is ruled out first because it is the cheapest fix.
- Reversing valve operation. With the system running, the technician listens for the solenoid click when the system switches to heat mode and feels the refrigerant lines to confirm the flow has reversed. If the valve does not switch, the solenoid coil is tested for voltage and continuity before the valve itself is condemned.
- Refrigerant charge and pressures. Gauges are connected to read suction and discharge pressures. Low suction pressure combined with a frosted outdoor coil points to a low charge, and the technician then searches for the leak using an electronic leak detector.
- Defrost cycle test. The technician manually initiates a defrost cycle or monitors an automatic one to confirm the defrost board, defrost sensor, and reversing valve all cooperate. A board that never calls for defrost, or a sensor that reads incorrectly, is identified here.
- Auxiliary heat strip test. The air handler is opened and the heat strips are tested with an ammeter to confirm they draw current when energized. A strip that reads zero amps has an open element or a failed sequencer.
- Electrical and breaker check. Line voltage at the outdoor unit and air handler is confirmed, breakers are inspected for signs of tripping or thermal damage, and all connections are checked for tightness.
This full diagnostic takes the guesswork out of the repair and protects you from paying for a part that was not the actual cause. To schedule one, call (863) 875-5500.
Safe Homeowner Checks Before Calling
There are a few safe steps you can take before a technician arrives. None of these require opening electrical panels or handling refrigerant.
- Switch to emergency heat. If your thermostat has an emergency heat setting, switch to it. This turns off the outdoor heat pump and runs only the electric heat strips, which can keep the home warm while you wait for service. Note that emergency heat costs more to run, so use it only as a temporary measure.
- Check the thermostat. Confirm it is set to heat, the temperature is set above the current room temperature, and the batteries are good. If you have a smart thermostat, check that it did not reset to defaults after a power outage.
- Check the breakers. Locate the indoor and outdoor breakers and confirm both are on. If one has tripped, reset it once. If it trips again, leave it off and call for service.
- Look at the outdoor unit. If the coil is buried in ice, do not chip it with a tool. Turn the system off and let the ice melt naturally, or set the thermostat to cooling and run the outdoor fan to speed melting, then switch back to emergency heat.
- Check the air filter. A badly clogged filter restricts airflow and can mimic a heating failure. Replace it if it is dirty.
Do not attempt to test refrigerant, open the air handler electrical compartment, or bypass any safety switches. Heat strips and capacitors operate at line voltage and can deliver a serious shock. If the checks above do not identify an obvious cause, call Top Notch Air Conditioning & Heating at (863) 875-5500.
When to Repair vs Replace Your Heat Pump
A heat pump heating failure does not automatically mean the system is done. Most single-component failures on a system under 10 years old are worth repairing. The decision gets harder when the equipment is older or when multiple components fail at once. Here is how we frame the choice during a diagnostic:
- System age under 10 years. If the equipment is under a decade old and the failure is a single part (a defrost board, a reversing valve solenoid, a heat strip), repair is almost always the right call. The rest of the system still has useful life.
- System age 12 to 15 years. Heat pumps in Central Florida typically last 12 to 15 years before major components start failing in clusters. If you are facing a compressor or coil repair on a system this old, replacement usually delivers better long-term value.
- R-22 refrigerant. Older systems that use R-22 (phased out in 2020) are expensive to service because the refrigerant is scarce. A leak repair on an R-22 system is often the trigger point to upgrade to a modern R-410A or R-454B system.
- Repair cost exceeds half of replacement value. If the quoted repair is more than half of what a new system would cost, replacement deserves serious consideration, especially on older equipment.
- Comfort problems beyond this failure. If your home has uneven temperatures, high humidity, or high electric bills in addition to the heating failure, a properly sized replacement system can solve multiple problems at once.
Top Notch Air Conditioning & Heating gives you a straightforward repair vs replace assessment after the diagnostic. We do not push replacement when a repair is the smarter financial choice. Carrier equipment installed by our team carries a 10-year parts warranty. To get an honest evaluation, call (863) 875-5500.
Preventing Heat Pump Heating Failures in Bartow
Most heating failures happen on the first cold morning of the season because the system has not been exercised in heating mode for months. A few habits catch problems early:
- Schedule a fall maintenance visit. A professional visit before cold weather includes checking the reversing valve, testing the defrost cycle, inspecting the heat strips, and confirming the refrigerant charge. Catching a weak defrost sensor in October prevents a no-heat call in January.
- Change the air filter regularly. Restricted airflow stresses the entire system and can contribute to coil frosting. In Bartow homes with pets or heavy oak pollen, check the filter monthly during peak season.
- Keep the outdoor unit clear. Trim shrubbery back at least two feet from the outdoor coil and remove leaves and debris. Restricted airflow across the outdoor coil accelerates frost buildup in heating mode.
- Test heating mode early. Run the system in heat mode on a mild October evening before you actually need it. If it blows cold air or never switches out of cooling, you find out before a cold front arrives.
- Consider a surge protector. Lightning and power surges damage defrost boards and reversing valve solenoids. A dedicated HVAC surge protector is an inexpensive safeguard.
Our Yeti Club maintenance plan includes one annual tune-up per system, priority scheduling, and 10% off repairs, for $199 per year. It is the easiest way to make sure your heat pump is ready before the first cold snap reaches Bartow.
FAQ: Heat Pump Not Heating in Bartow
Why is my heat pump blowing cold air in Bartow?
The most common reason a heat pump blows cold air during a heating call is a stuck reversing valve, which leaves the system stuck in cooling mode. Other causes include low refrigerant charge, a failed defrost control board, an iced outdoor coil, failed auxiliary heat strips, a tripped breaker, or a bad thermostat. Switch the thermostat to emergency heat as a temporary measure and call Top Notch Air Conditioning & Heating at (863) 875-5500 for a $99 diagnostic.
How much does heat pump heating repair cost?
In Bartow and Polk County, a reversing valve replacement typically runs $450 to $900, a defrost control board replacement runs $300 to $650, auxiliary heat strip replacement runs $250 to $600, and a refrigerant recharge runs $250 to $700 depending on the refrigerant and leak repair. Every repair starts with a $99 diagnostic visit to confirm the exact failure before any work is quoted.
Can a low refrigerant charge cause no heat?
Yes. A heat pump relies on the correct refrigerant charge to absorb heat from outdoor air, even when temperatures are in the 40s or 50s. When the charge is low, the outdoor coil runs too cold, frost accumulates faster than the defrost cycle can clear it, and the system cannot extract enough heat to warm the home. A low charge also points to a leak that must be located and repaired before recharging.
Should I replace my heat pump or repair it?
If your heat pump is under 10 years old and the repair is a single failed component, repairing is usually the better value. If the system is over 12 to 15 years old, uses R-22 refrigerant, or the repair cost exceeds half the price of a new system, replacement deserves serious consideration. Top Notch Air Conditioning & Heating gives a straightforward repair vs replace assessment after the diagnostic visit.
How fast can Top Notch reach Bartow?
Top Notch Air Conditioning & Heating offers same-day service Monday through Saturday, 8 AM to 5 PM. Bartow sits roughly 15 miles from our Winter Haven headquarters, so most calls are reached the same day during business hours. We are closed on Sundays. Call (863) 875-5500 to schedule.
Related Services in Bartow
If your heat pump failure points to a larger system issue, we may recommend follow-up options like heat pump repair, heating repair, or AC installation and replacement when age and cost make replacement the better value. You can also learn more about our local coverage on the heating repair in Bartow, FL page, and see our full range of services including AC repair in Bartow, FL for cooling season needs.