Reliable Geothermal Repair From Experienced Heating Specialists
A geothermal heating system is one of the most efficient ways to heat your home, but when it malfunctions, specialized knowledge is essential. Harmon Heating & Cooling has 35+ years of experience repairing geothermal systems in Indiana homes. Our technicians understand heat pump cycles, ground loop integrity, and the electrical controls that make geothermal systems work.
Geothermal problems demand specialized diagnosis. We use pressure gauges, electrical testers, and system monitors to identify exactly what's failing. A thorough inspection leads to the right repair — and the right fix saves money on parts and future repairs.
Ready to upgrade instead? Explore geothermal installation or replacement, or protect your system with maintenance.
Specialized Diagnostics
35+ Years of Experience
Honest Repair Guidance
Manufacturer-Trained
Local to Fishers
Catching any of these early usually means a smaller repair bill — and no cold days without the efficient heating you count on.
If your geothermal system runs but barely heats, or won't heat at all, suspect a refrigerant leak, compressor failure, reversing valve malfunction, or ground loop problem. We test refrigerant pressure, ground loop flow, and compressor operation to find the culprit.
Geothermal's main advantage is efficiency. If your bills spike without change in occupancy or comfort settings, the system is likely running harder than it should. A refrigerant leak, poor ground loop circulation, or failed component forces the compressor to work overtime.
Refrigerant has a distinctive odor; a strong smell near the indoor unit or outdoor loop access points signals a leak. Visible oil pooling at connection points also indicates refrigerant loss. Both require immediate attention.
Grinding, squealing, or hissing sounds from the compressor mean mechanical wear or refrigerant flow problems. A failing ground loop pump produces whining or loss of flow noise. These are not noises to ignore.
A sudden drop in pressure or flow indicates a leak in the buried lines or a failing circulation pump. Ground loop problems are complex but critical — the loop is the heart of geothermal efficiency.
If temperature adjustments don't trigger system response, or the system cycles on and off rapidly, suspect a failed control board, sensor failure, or compressor short-cycle issue. These electrical problems demand diagnostic testing.
Five steps from your first call to a system we've watched run at full heating load before we leave.
Contact us and describe what you're noticing — loss of heating, unusual sounds, high bills, or erratic cycling. We'll schedule a comprehensive inspection at a time that works for you. Geothermal diagnostics take time, so we block adequate appointment windows (typically 1–2 hours).
We run a complete diagnostic: refrigerant pressure checks and leak detection, ground loop flow and temperature measurement, compressor amp draw, reversing valve operation, thermostat response, and electrical control testing. Proper diagnosis is everything — it determines whether you need a simple fix or major component replacement.
Once diagnostics are complete, we explain what's wrong in plain language. We present your options — repair the failing component, replace it with a quality part, or, if major components are nearing end of life, discuss whole-system evaluation. You get an upfront quote with no surprises, plus financing options if needed.
Once you approve, we order parts if needed and complete the repair to manufacturer specifications. Geothermal repairs often involve EPA-certified refrigerant work, which we handle with full compliance. After repair, we pressure-test, recharge if necessary, and run the system at full capacity to verify heating performance and safety operation.
We explain how to maintain your geothermal system to prevent future failures — flushing the ground loop, checking refrigerant integrity, and testing controls keeps everything running at peak efficiency. We offer a maintenance plan tailored to geothermal systems, and you can call us with follow-up questions any time after the visit.
These are the failures we diagnose and repair most often on residential geothermal heating systems.
A refrigerant leak destroys your system's efficiency and can damage the compressor. We use leak detection tools to find leaks in indoor coils, outdoor connections, and piping, then repair the leak, recover and recycle refrigerant per EPA rules, and recharge to proper specifications.
The compressor is the geothermal system's engine. A failing compressor loses pressure, runs hot, or draws excessive current. If rebuild is viable we perform the work; if replacement is needed, we install a quality compressor, verify charge, and test full system operation.
Over time, mineral deposits and sediment can clog the buried loop, reducing flow and efficiency. We flush the system with specialized equipment to clear blockages. If the circulation pump fails, we replace it. Loop integrity directly impacts your heating efficiency.
The reversing valve lets your heat pump switch between heating and cooling modes. If it sticks or fails, the system may be stuck in one mode or cycle erratically. We test, clean, or replace the reversing valve, restoring proper mode switching.
A failed control board or sensor prevents the system from responding to temperature commands. We test electrical circuits, sensor function, and logic, then repair or replace failed components to restore proper thermostat response and cycling.
Electrical capacitors and relays power the compressor and fan motors. A failed capacitor can prevent startup; a failed relay stops the compressor. We test and replace these as needed, restoring electrical function without major expense.
If your system has been open to air, we must evacuate (remove all air and moisture), pull a deep vacuum, and recharge with the correct refrigerant type and quantity. This is EPA-governed work performed by certified technicians only — we handle it with full compliance.
All parts we install come with manufacturer warranty, typically 5–10 years depending on the component. Labor is warranted for one year, and geothermal-specific work like ground loop repair carries the same professional guarantee.
Geothermal systems reward regular care. Protect your investment with our maintenance plan, which includes annual ground loop flushing, refrigerant integrity checks, and full system testing. Regular maintenance catches issues early, maintains peak efficiency, and extends your system's lifespan significantly.
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 geothermal heating systems across Central Indiana. Fishers is our home base and gets the fastest response times, with Westfield just west, Noblesville north, Fortville to the 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 to upgrade to a new, high-efficiency geothermal system? 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 geothermal system leaves you without one of the most efficient heating sources available. Harmon Heating & Cooling brings manufacturer training, specialized diagnostic tools, and 35+ years of heating expertise to every geothermal repair. We find the real problem, explain your options honestly, and restore your system's efficiency and reliability — no guessing, no unnecessary part replacement.
Call 317-588-8303 or schedule a geothermal repair inspection today. Flexible financing available — spread repair or replacement costs over manageable monthly payments.
