Expert Diagnosis and Repair for Your Ductless System
A mini-split heat pump provides efficient heating and cooling with zone control—until something stops working. When your mini-split system loses heating, cooling, or refrigerant, you lose both comfort and efficiency. Harmon Heating & Cooling has 35+ years of heat pump expertise and can diagnose and repair mini-split systems from LG, Armstrong Air, and other brands.
Mini-split repairs require precision diagnosis. We test refrigerant pressure, electrical function, and air output to identify the exact failure point. A thorough inspection prevents guesswork and leads to the right, efficient repair.
Request a mini-split repair estimate, explore mini-split installation options, or protect your system with a maintenance plan.
Precision Diagnostics
35+ Years of Experience
EPA-Certified Refrigerant Work
Manufacturer-Trained
Local to Fishers
Catching any of these early usually means a smaller repair bill — and a system that stays efficient.
If your indoor unit runs but no conditioned air comes out, suspect a refrigerant leak, compressor failure, or reversing valve malfunction. Loss of conditioning is the clearest sign something is seriously wrong. We test pressures and electrical function to find the culprit.
Conditioned air comes out weakly, or one room cools while another stays warm. This points to a clogged filter, blocked ductless outlet, or failing compressor. A weak system overworks and wastes energy.
A distinctive refrigerant odor near the indoor unit or outdoor condenser signals a leak. Visible oil or fluid pooling at connection points also indicates refrigerant loss. Low refrigerant cuts efficiency and damages the compressor. This demands immediate attention.
Grinding, squealing, hissing, or rattling from the compressor or indoor unit means mechanical wear or refrigerant issues. These noises precede failure—don't wait for total shutdown.
Rapid cycling (short bursts of operation) stresses the compressor and signals control issues, thermostat failure, or refrigerant problems. Erratic cycling is a red flag.
If bills spike without change in comfort settings, your mini-split is overworking due to refrigerant loss, compressor strain, or failed components. A repair that restores efficiency saves money fast.
Five steps from your first call to a system you've watched us test in both heating and cooling before we leave.
Contact Harmon Heating & Cooling by phone or online. Describe what you're noticing. We'll schedule a diagnostic appointment with enough time to run complete tests on your system. You describe the problem and any recent changes, we confirm an appointment at your convenience, our technician arrives with full diagnostic equipment, and we confirm access to indoor and outdoor units.
We test refrigerant pressure, electrical circuits, compressor amps, reversing valve operation, air output, and thermostat response. We use gauges, multimeters, and thermal imaging to see exactly what's happening. Professional diagnostics reveal the real failure—no guessing—and we document our findings with photos and notes.
We explain the failure clearly in plain language. If it's a refrigerant leak, we show you where. If the compressor is failing, we describe the symptoms. We present repair options and costs with a written estimate, a repair-vs-replacement trade-off analysis, a parts timeline, warranty on parts and labor, and financing options if needed — and you decide before any work begins.
We perform the repair to manufacturer specifications. If refrigerant work is involved, we recover, evacuate, and recharge with EPA compliance. We pressure-test all connections, verify proper operation in both heating and cooling modes, confirm efficient air output, and run electrical and safety checks before we finish.
We explain how to maintain your mini-split to prevent future failures with homeowner guidance on filters and maintenance and recommendations for preventive care. We offer a maintenance plan that includes annual cleaning, filter changes, and system inspection, and you can call us with follow-up questions after the visit. Your mini-split will stay efficient and reliable with regular care.
These are the failures we diagnose and repair most often on ductless mini-split heat pump systems.
Refrigerant leaks destroy efficiency and damage the compressor. We use electronic, dye-enhanced, and UV detection methods to find leaks. Once located, we repair the leak, recover and recycle refrigerant per EPA rules, and recharge the system to proper charge.
The compressor is the heart of the system. A failing compressor loses pressure, runs hot, or draws excessive current. We repair or replace with quality OEM parts, verify charge, and test full system operation.
The reversing valve switches between heating and cooling. If it sticks, the system may be stuck in one mode or cycle erratically. We test, clean, or replace the valve, restoring proper mode switching.
A stuck or failed expansion valve blocks refrigerant flow and destroys cooling/heating. We test and replace with a quality component, restoring proper refrigerant metering.
Electrical failures prevent system response and proper operation. We test boards and sensors, repair or replace failed components, and restore thermostat control.
Clogged coils reduce heat transfer and efficiency. We clean indoor and outdoor coils professionally, restoring cooling and heating capacity. For mini-splits, coil cleaning is fast and effective maintenance.
A clogged filter restricts airflow and forces the system to overwork. We replace filters and verify clear airflow. For mini-splits, regular filter changes prevent most efficiency problems.
Loose connections, burned contactors, or failed wiring prevent proper operation. We test electrical components, repair connections, and replace failed parts to restore safe, reliable function.
Mini-split systems run most efficiently with regular care. Protect your investment with our maintenance plan, which includes annual filter changes, coil cleaning, refrigerant verification, and system inspection.
A new HVAC system is a real investment, and Harmon Heating & Cooling works with Service Finance to help make that investment manageable. Whether you're replacing an aging furnace before winter or upgrading to a more efficient central AC system, financing options are available so an unexpected repair or planned upgrade doesn't have to wait.
Our team can walk you through financing options through Service Finance at the time of your estimate, so you know what to expect before any work begins.
Contact Us to ApplyDon't wait on a failing furnace or AC — get your system installed today and spread the cost into manageable monthly payments.
Flexible terms keep payments predictable, so a new system fits your budget instead of draining your savings all at once.
Financing makes it easier to step up to a more efficient Armstrong system that lowers your energy bills month after month.
We repair ductless mini-split heat pump systems across Central Indiana. Fishers is our headquarters and gets local service, with Westfield just west, Noblesville north, Fortville east, Pendleton to the southeast, and Carmel to the south.
Don't see your city listed? Harmon Heating & Cooling serves additional communities throughout Central Indiana beyond our primary service area — reach out and we'll let you know if we cover your address.
Ready for a new, high-efficiency mini-split system, or not sure which service you need? These are the paths we can walk you through, and the same team handles all of them.
A broken mini-split leaves you without efficient heating and cooling. Harmon Heating & Cooling brings EPA-certified refrigerant expertise, manufacturer training, and 35+ years of heating experience to every mini-split repair. We diagnose precisely, explain honestly, and restore your system to full efficiency. Our family-owned team stands behind every repair.
Call 317-588-8303 to describe your problem and schedule a repair visit. Flexible financing available through Service Finance — see our financing options.
