Furnace and Heat Pump Repair in Fishers, IN
Thornton Plumbing HVAC and Electrical repairs furnaces, heat pumps, and dual-fuel heating systems for Fishers, IN homeowners, with 24/7 emergency service when the heat quits. Our HVAC technicians work under Indiana HVAC License HH1800018, backed by Indiana Plumbing License PC11500008 and Indiana Electrical License EC2500017, so the gas piping, condensate drains, and electrical connections around your system are handled by licensed trades. We are fully bonded and insured and have been BBB A+ rated since 2006. Furnaces and heat pumps in Fishers work hard from October through March, with an Indianapolis-area average January low of 20.9°F, and a repair that traces the real failure is the difference between one visit and three. Call 317-697-9265 for heating repair anywhere in Fishers.
What Heating Repair Covers in Fishers
A heating repair finds out why a furnace, heat pump, or dual-fuel system stopped heating, heats unevenly, or is running in a way that damages itself, and then fixes the part responsible. In a Fishers home, that can mean an ignition fault in a furnace, a frozen condensate line, a heat pump stuck in defrost, or a thermostat that no longer talks to the equipment. Our furnace and heat pump repair service covers the whole range.
Fishers has grown from 76,794 residents in the 2010 Census to an estimated 104,812 in 2025, according to the U.S. Census Bureau, and about 76 percent of households own their homes. Newer homes are more likely to have high-efficiency condensing furnaces and heat pumps, and older ones near the Geist Reservoir and in established neighborhoods are more likely to have standard-efficiency furnaces. Each type fails in its own ways, and the table below shows the patterns we see most.
They got the job done professionally and efficiently
Common Furnace and Heat Pump Problems in Fishers Homes
| Symptom | Common causes | What the technician checks |
|---|---|---|
| Furnace runs but the air is cool | Failed igniter or flame sensor, tripped limit switch, interrupted gas supply, thermostat fan setting | Ignition sequence, flame signal, airflow, thermostat settings and wiring |
| Furnace starts, runs briefly, and shuts off | Dirty flame sensor, restricted airflow, clogged condensate drain, overheating | Flame sensor, filter and blower, condensate trap and safety switch, limit switch |
| A blinking light or error code on the control board | Pressure switch, inducer, flame, limit, or lockout faults | Code history, then the component the code points to |
| No heat after a snowfall | Snow or ice over PVC intake or exhaust terminations, frozen condensate line | Vent terminations, condensate line, trap, and drain |
| Cold rooms upstairs or over the garage | Duct leaks, closed dampers, undersized returns, dirty filter | Airflow at the registers, blower, duct connections, zone dampers |
| Heat pump blows cool air in winter | Normal defrost cycle, failed reversing valve, low refrigerant, thermostat in the wrong mode | Defrost operation, reversing valve, refrigerant pressures, thermostat settings |
| Ice that does not clear from the outdoor unit | Defrost control or sensor failure, blocked airflow, refrigerant issue | Defrost board and sensors, fan motor, coil condition |
| Noises such as banging, squealing, or rattling | Delayed ignition, worn motor bearing, loose panels or ducts | Burners and ignition, inducer and blower motors, panels and duct supports |
| Thermostat blank or unresponsive | Dead batteries, tripped switch or breaker, blown board fuse, wiring fault | Power at the furnace, board fuse, thermostat wiring |
| Breaker trips when the furnace starts | A failing blower or inducer motor, shorted igniter, damaged wiring | Amp draw, motor windings, and wiring, with a licensed electrician involved if the circuit is at fault |
Furnace and Heat Pump Repair Services We Provide in Fishers
Gas and Electric Furnace Repair
Furnace repairs in Fishers most often involve hot surface igniters, flame sensors, inducer motors, pressure switches, blower motors and capacitors, limit switches, gas valves, and control boards. Technicians test each stage of the start-up sequence in order, which isolates the failure without replacing parts that are working. Electric furnaces get the same method, with heating elements, sequencers, and limit controls as the main suspects.
High-Efficiency Condensing Furnace Repair
A furnace rated at 90 percent AFUE or higher recovers extra heat from its exhaust, and the Department of Energy describes this as condensing flue gases in a second heat exchanger. The result is water that has to drain, plus PVC intake and exhaust pipes that terminate outside the house. Clogged traps, frozen condensate lines, ice-covered terminations, and failed pressure switches are the usual reasons these furnaces lock out, and they show up often after the first hard freeze.
Heat Pump Repair
Heat pumps carry a refrigerant circuit, reversing valve, defrost control, and outdoor fan and compressor on top of the electrical parts. Our technicians test defrost operation, the reversing valve, contactors, capacitors, fan motors, and auxiliary heat strips. Problems on the cooling side of the same unit are handled through our air conditioning repair service in Fishers.
Dual-Fuel and Hybrid System Repair
A dual-fuel system uses the heat pump in milder weather and the gas furnace in the coldest, with shared ductwork. Repairs include the changeover control that decides which half runs, as well as each half separately. A failure in one half often goes unnoticed because the other covers, so Thornton tests both.
Thermostat and Smart Control Repair
Thermostat problems in newer Fishers homes often come from wiring and compatibility, not the thermostat itself. We test low-voltage wiring and common-wire connections, repair or replace thermostats, and confirm each zone calls for heat correctly.
Airflow, Blower, and Duct-Related Repair
Airflow problems sit behind uneven rooms and many short-cycling complaints. The Department of Energy notes that ducts in attics or garages can lose up to 35 percent of a furnace’s output, which is why a room over a garage can stay cold with a healthy furnace. For rooms that never heat well because of how the house was built or added onto, a ductless mini-split in Fishers can provide heating and cooling without extending ductwork, and dust or air quality concerns can be paired with our indoor air quality services in Fishers.
Emergency Heating Repair
A heating failure on a freezing night is an emergency for a household. Thornton provides 24/7 dispatch for Fishers, so a licensed technician can begin diagnosis at any hour. Call 317-697-9265.
When the Heat Goes Out: What to Do First
- Check the thermostat: mode set to Heat, target above the room temperature, batteries fresh
- Check the furnace power switch and the breaker, and replace a dirty filter
- Look outside for snow or ice over the PVC vent terminations or the heat pump, and clear them by hand
- If a carbon monoxide alarm sounds or you smell gas, go outside and call 9-1-1 or your gas utility before anything else
- If none of those restore heat, call 317-697-9265 and describe what the furnace does when it tries to start
- Keep interior doors open to heated rooms and close off unused spaces while you wait
The Consumer Product Safety Commission recommends carbon monoxide alarms on every level of the home and outside sleeping areas, tested monthly, and an annual professional inspection of fuel-burning heating systems.
Gas, Electric, and Heating in Fishers: Who Handles What
The City of Fishers lists CenterPoint Energy for natural gas and Duke Energy and NineStar for electric service on its flood resources. Those utilities handle service up to your meter. Everything on the home side of the meter, from the furnace to the gas piping and the electrical connection, is licensed-trade work, and Thornton holds all three Indiana licenses that apply. If you smell gas, call CenterPoint Energy or 9-1-1 from outside the home; if the power is out, call your electric provider; if the furnace or heat pump will not run once service is on, call Thornton.
Furnace and Heat Pump Checks After the August 2026 Flood in Fishers
The City of Fishers reports that the Mayor issued a Local Disaster Emergency Declaration on August 15, 2026, that the White River, Fall Creek, and other bodies of water rose to historic levels, and that 16 homes in two neighborhoods were evacuated. Homes that stayed dry above the slab still saw saturated ground and sump pumps running for days, as the National Weather Service documented.
Furnaces, air handlers, and outdoor units sit low, where water can reach burners, blowers, and control boards. The Air-Conditioning, Heating, and Refrigeration Institute advises that flood-damaged heating and cooling equipment be replaced rather than repaired, with a qualified technician making the call. If water reached your equipment, call before restarting it. A sump pump that ran far beyond its normal duty is also worth testing through our sump pump service, and a water heater that sat in water needs the checks described on our water heater flood damage. The City advises contacting your insurance company before any remediation begins (see the City of Fishers flood recovery resources), so photograph equipment labels and any visible damage first.
Repair or Replace in Fishers: How the Decision Usually Goes
ENERGY STAR lists a furnace more than 15 years old, or a heat pump more than 10 years old, as a point to consider replacement, along with frequent repairs paired with rising energy bills, rooms that run too hot or too cold, and a noisy system. In practice, the decision falls out of a few questions:
- Repair is usually the right call when the equipment is under those ages and the failure is a normal wear item, such as an igniter, flame sensor, capacitor, contactor, or thermostat.
- Replacement deserves a look when an older system has needed repeated repairs, when a technician confirms a cracked heat exchanger, or when a heat pump has a major refrigerant-side failure.
- A second opinion on the whole system, including ductwork and sizing, is reasonable when several comfort problems appear at once.
Thornton explains both options and the reasoning behind them, and the decision stays with you. Our heating installation service in Fishers covers sizing and installation when replacement is the better path, and financing is available for qualifying projects.
Our Heating Repair Process in Fishers
- Call 317-697-9265 and describe the symptoms, the equipment type, and how the thermostat behaves
- A licensed HVAC technician is dispatched to your Fishers address
- The technician checks for gas odor and venting concerns before opening any equipment
- The failure is traced through the heating sequence, testing electrical supply, ignition, airflow, and controls
- You hear what failed, what caused it, and the repair options before any work begins
- The repair is completed once you approve the scope of work
- The system runs through a full heating cycle to confirm steady operation and thermostat response
- Related items worth watching, such as filter condition, vent terminations, or equipment age, are reviewed with you
How to Prevent the Next No-Heat Call
Repair fixes today’s failure, and maintenance reduces the odds of the next one. Our heating maintenance service in Fishers cleans the parts that fail first and tests safety controls and venting before the cold arrives. The Thornton Family Club is Thornton’s maintenance membership for homeowners who want that yearly visit scheduled.
Permits and Local Codes for Heating Work in Fishers
A repair such as an igniter or flame sensor replacement is usually treated as service work. A furnace or heat pump replacement, a venting change, or new gas piping or a new circuit may involve a building permit and inspection through the City of Fishers. The City can confirm what applies to your address, and Thornton coordinates permit requirements for applicable work under its Indiana licenses, so the paperwork does not land on you.
Why Fishers Homeowners Choose Thornton for Heating Repair
| What We Offer | What It Means for You |
|---|---|
| Indiana HVAC License HH1800018 | Licensed HVAC technicians diagnose and repair furnaces, heat pumps, and dual-fuel systems |
| Indiana Plumbing License PC11500008 | Gas piping, condensate drains, and water heater connections in the mechanical room are handled by licensed plumbers |
| Indiana Electrical License EC2500017 | Furnace and heat pump circuits, disconnects, and breaker problems are handled by licensed electricians in the same visit |
| BBB A+ Rated Since 2006 | Third-party verified record of honest service across Hamilton County |
| Fully Bonded and Insured | Zero liability for you if anything goes wrong on site |
| 24/7 Emergency Dispatch | Help when the heat goes out at any hour, including nights, weekends, and holidays |
| Diagnosis Before Parts | A repair plan based on the failed component, explained before work begins |
| Furnaces, Heat Pumps, and Dual-Fuel Systems | One team for every type of residential heating system found in Fishers homes |
| GreenSky Financing Available | Payment options for qualifying repairs and replacements |
| Thornton Family Club | A maintenance membership that keeps yearly tune-ups on the calendar |
Check our licenses with the Indiana Professional Licensing Agency and review our record at the Better Business Bureau. Fishers neighbors share their experiences on our testimonials, and our financing explains GreenSky options for qualifying projects.
Frequently Asked Questions: Heating Repair in Fishers, IN
Who should I call first when my furnace stops working in Fishers?
Call Thornton at 317-697-9265 for any furnace or heat pump that stops heating, and a licensed HVAC technician will be dispatched at any hour. If you smell gas, leave the home and call your gas utility or 9-1-1 from outside. If the whole house has lost power, call your electric provider first, since a furnace cannot run without electricity.
How fast can Thornton reach my Fishers home during a cold snap?
Thornton provides 24/7 emergency dispatch for Fishers, including nights, weekends, and holidays. Cold snaps create the busiest days of the year, so arrival timing depends on call volume. Call as soon as the system quits to get the earliest available window.
Why is my furnace blowing cold air in Fishers?
Cold air usually means the burners did not light or shut off early, which points to a worn igniter, a dirty flame sensor, a tripped limit switch, or an interrupted gas supply. A thermostat set to Fan instead of Auto can also blow unheated air. Our article on why a furnace blows air but does not heat lists the checks, and a Thornton technician can pin down the cause.
What does a blinking light or error code on my furnace mean?
Most furnaces flash a code on the control board to report the last fault, such as a pressure switch that did not close, a flame that was not detected, or a limit switch that tripped. The code points to a circuit, not always to a failed part, so repeatedly resetting the furnace only hides the pattern. A technician reads the code history and tests the component behind it, as our guide to troubleshooting common heating repair issues describes.
Why does my furnace stop working when it gets very cold outside?
Extreme cold exposes marginal parts and conditions. A high-efficiency furnace can lock out when its condensate line freezes or its vent terminations ice over, a worn igniter or flame sensor may fail after weeks of light use, and a heat pump may run out of capacity and lean on auxiliary heat. The pattern of when the failure happens helps a technician narrow the cause.
Can snow or ice block my furnace vent?
Yes. High-efficiency furnaces vent through PVC pipes that exit the side of the house, and drifted snow or ice can cover the intake or exhaust. The U.S. Department of Energy notes that sealed-combustion units draw outside air directly to the burner and send exhaust outdoors, so a blocked termination can shut the furnace down. Clear snow from around the terminations by hand if you can do so safely, and leave any pipe repair to a technician.
What should I do if I smell gas near my furnace?
Leave the home right away, avoid switches, flames, and anything that could spark, and call your gas utility or 9-1-1 from a safe distance. The City of Fishers lists CenterPoint Energy as the gas provider in the community. Gas leaks require immediate attention from a licensed professional, and Thornton inspects the furnace and gas connections once the utility has cleared the service.
Is my heat pump supposed to keep up when it is below freezing?
Often, but not always. The Department of Energy says cold climate heat pumps are designed to perform in temperatures as low as 5°F, and the Indianapolis average January low, the closest published reference for Fishers, is about 21°F, so a healthy heat pump handles most winter days. As temperatures fall, capacity drops and auxiliary heat helps. If the system runs on auxiliary heat in mild weather, or cannot hold temperature on moderately cold days, it needs a diagnosis.
Why is my heat pump blowing cool air in the winter?
A brief burst of cooler air is normal during a defrost cycle, when the unit briefly reverses to melt frost from the outdoor coil. Air that stays cool points to a stuck reversing valve, low refrigerant, a failed defrost control, or a thermostat set to the wrong mode. A technician tests each to find the cause.
Is steam or fog around my outdoor heat pump normal?
Yes, during a defrost cycle. The melting frost can produce a plume of vapor and a little dripping, and the unit returns to heating afterward. Thick ice that stays on the coil, a fan that is not turning, or defrost cycles that never seem to finish are signs that something has failed.
What is the difference between a heat pump and a dual-fuel system, and can Thornton repair both?
A heat pump moves heat between the outdoors and the house using electricity. A dual-fuel system pairs a heat pump with a gas furnace, and the Department of Energy notes that the heat pump handles most heating in milder weather while the furnace takes over in colder temperatures. Thornton repairs heat pumps, furnaces, and the controls that switch between them.
How do I tell whether the thermostat or the furnace is the problem?
If the thermostat screen is blank, check batteries first, then the furnace power switch and breaker. If the screen works and the furnace does not respond, the fault may be wiring, a setting, or the furnace itself. A technician tests voltage at the thermostat and the control board to separate the two quickly.
Can Thornton repair smart thermostat wiring and compatibility problems?
Yes. Smart thermostats need the right low-voltage wiring, often including a common wire, and a mismatch can cause dropouts or missed calls for heat. Thornton’s technicians test the wiring, correct it, and confirm the thermostat communicates with the furnace or heat pump.
Why does my furnace run constantly in cold weather?
In very cold weather a furnace runs longer cycles because the house loses heat faster, and that can be normal. Constant running with a house that never reaches the set temperature points to restricted airflow, duct leaks, an undersized system, or a failing component. The Department of Energy notes that a properly sized furnace operates most efficiently, so persistent long runs are worth a diagnosis.
Why do my upstairs rooms or the rooms over the garage stay cold?
Upper floors and rooms over garages sit at the far end of the duct system and lose heat through exposed walls and floors. Leaky ducts, closed dampers, or an undersized return make it worse. Our guide on why uneven heating across rooms traces back to missed maintenance explains what a technician checks.
How does a technician decide between repairing and replacing a furnace?
The technician weighs the age of the equipment, the part that failed, how often it has been repaired, and the condition of the heat exchanger. ENERGY STAR lists a furnace more than 15 years old, or a heat pump more than 10 years old, as a point to consider replacement. You receive both options and the reasoning before anything is decided.
My furnace is 15 years old and still runs. Should I keep repairing it?
That depends on what fails and how often. One normal wear item on a furnace with a sound heat exchanger is a reasonable repair. Several repairs in a short span, uneven heat, and rising energy use together suggest the system is wearing out. Thornton gives an honest assessment of both paths.
Does Thornton repair boilers?
Most homes in Fishers use forced-air furnaces or heat pumps, and those are the systems Thornton’s heating repair pages cover. If your home has a hot-water or steam boiler, call 317-697-9265 with the make and model and the team will confirm whether it can help.
My basement flooded in August. Should I have the furnace checked before using it?
Yes, if water reached the furnace, air handler, outdoor unit, or their controls. The Air-Conditioning, Heating, and Refrigeration Institute advises replacing flood-damaged heating equipment rather than repairing it. Read our guide on running a furnace or AC after a basement flood before restarting anything.
Which Fishers neighborhoods does Thornton serve for heating repair?
Thornton serves all of Fishers, including Saxony, Harrison Pond, Sunblest Farms, Thorpe Creek, the Geist Reservoir area, and newer developments along I-69 and SR 37, along with neighboring Hamilton County communities.
Who do I call if the power is out and the furnace will not run?
Call your electric provider. The City of Fishers lists Duke Energy and NineStar for electric service, and your bill shows which one serves your address. Once power returns, a furnace that does not restart, or a heat pump that stays off, is a job for Thornton at 317-697-9265.
Do heating repairs in Fishers require a permit?
Most repairs, such as an igniter, flame sensor, capacitor, or thermostat replacement, are service work. A furnace or heat pump replacement, a venting change, or new gas piping or circuits may involve a permit and inspection. The City of Fishers can confirm what applies to your address, and Thornton coordinates permit requirements for applicable work under its Indiana licenses.
Does Thornton explain the repair before work begins?
Yes. You hear what failed, what caused it, and the repair options before any work starts, and the repair goes ahead only with your approval. The technician then runs the system through a full heating cycle to confirm it is working properly.
Does Thornton offer financing if a furnace has to be replaced?
Yes. Thornton offers GreenSky financing for qualifying projects. Ask the technician about it during the visit, or call 317-697-9265.
How do I schedule heating repair in Fishers with Thornton?
Call 317-697-9265 at any hour. Describe the symptoms, share the make and model if you can, and a licensed technician will be dispatched to your Fishers address.
Areas Near Fishers We Also Serve
Thornton repairs heating systems throughout Hamilton County and the northeast side of Indianapolis. Nearby communities include:
- Carmel, IN, including heating repair in Carmel
- Geist, IN
- Castleton, IN
- Westfield, IN
- Cicero, IN
- Noblesville and the rest of Hamilton County on our service area page
For everything else Thornton does for Fishers homes, see our plumbing, heating, and electrical services in Fishers, or explore our heating services across the region.
No Heat in Your Fishers Home? Call Thornton Now
