When To Repair A Geothermal System And When To Replace It

I am Dave Hartzell. 45+ years in HVAC, 15+ years running Hartzell’s Heat & Air out of Kingfisher, IGSHPA accredited. The question I get most on a geo call is always the same: do I fix this thing, or replace it?

The $348 diagnostic buys a written verdict and replacement quote

A geothermal diagnostic is $348 flat, any hour. Weekday, weekend, or the middle of the night, same number, paid up front. It buys a full performance audit: loop pressure, refrigerant charge, desuperheater, controls, and heat exchanger, plus a written report and quote before I leave.

Repair and replacement work is quoted separately before approval.

That split is deliberate. Testing your loop is the slow part of the visit, and it has value whether the answer is good news or bad.

What the other numbers are

A residential service call is $99 dispatch plus $111 diagnostic, $210 total. The tech gives a written repair estimate before repair work starts.

An emergency call on a standard system is $309, a $198 dispatch plus the $111 diagnostic, non-refundable. Geothermal is the exception: $348 flat whatever the hour. Light commercial up to 15 tons is a $389 flat diagnostic, day or night. A new system estimate is free. There is always a dispatch fee and always a diagnostic fee.

Why diagnosing geothermal is not like diagnosing an air conditioner

That is also why I carry the geothermal credentials and not just the general ones. I am IGSHPA accredited for ground loop work and a ClimateMaster GeoElite dealer for the equipment, so a repair or replace verdict is written against manufacturer data for your model, not against a general HVAC rule.

An air source heat pump is rated on outdoor air temperature. Geothermal is rated on entering water temperature, the temperature of the fluid coming back to the machine from your loop. Those are two different tests, which is why the two efficiency ratings are not the same kind of number.

That is not trivia. The loop in your yard is part of the machine. A geo that cannot hold your house may have nothing wrong inside the cabinet: flow could be down, the loop short on fluid, a flow center pump failing. A geo diagnosed by only opening the closet box is half a diagnosis.

Oklahoma pushes on both ends of the year. Across the seven counties I run daily, the 99% heating design temperature runs 13F to 15F and the 1% cooling design temperature runs 99F to 101F. A system that seems fine in April can be failing by late July.

Signs that say repair

One component failed and the rest tests healthy: a contactor, a capacitor, a board, a loop pump.
The loop holds pressure and flow is where it should be.
Charge is correct and the same leak has not come back before.
The cabinet is dry, the heat exchanger clean, the desuperheater working.
I can still get parts for it.

When one thing is wrong and everything else passes, I fix the one thing. That is a repair, the $348 stands as paid, and you keep the system you own.

Signs that say replace

A failed compressor in an older machine, where the repair is a large fraction of a new unit.
A refrigerant leak on the water side of the heat exchanger. Different animal than a line set leak.
Repeat failures. Several separate repairs in one season is a pattern, not bad luck.
It runs constantly, cannot make setpoint, and the backup heat is carrying the house.
Boards or controls nobody stocks any more, so the next failure has no fix.

If that is your system, I say so in writing and quote replacement separately before approval.

The tell I look for first: how hard your backup heat is working

Electric resistance backup is COP 1.0 by definition. One kilowatt hour of electricity delivers 3,412 Btu of heat and not one Btu more.

A working geothermal compressor moves several times that much heat on the same kilowatt hour. A limping geo leaning on its strip heat quietly bills you at resistance rates all winter while it still looks like it is running. If your January bill jumped and the thermostat will not reach setpoint, bring the bills outside with you.

The loop usually outlives the box

This is where a geothermal replacement stops resembling a conventional one. The loop is the buried, expensive half: roughly $3,000 per ton of capacity, and a vertical bore runs about 200 bore feet per ton. It is pipe in the ground, not the part with a compressor in it.

So on a house that already has geothermal, I test the loop first. If it holds pressure and flows right, the new job does not include a new loop, which makes it a very different job than a first install on a bare yard.

I am not printing a lifespan number for a loop or a heat pump. There is too much variation in how they were installed and maintained to hand you an average and call it your house. What I hand you is what your loop tested at, in writing.

Scope is why I will not print your price. Three real jobs, by town: a Broken Bow home at $42,497.15, a Lawton home at $23,825.00, a Piedmont home at $22,704.79. The estimate is free.

Rebates and the tax question

The residential federal tax credit under Section 25D has expired. I say it plainly because competitors still advertise it. Do not price a replacement around it. Commercial geothermal falls under Section 48, not 48E. Take tax questions to a tax professional.

Utility rebates are separate and still live. OMPA pays up to $800 per cooling ton in the municipal towns, including Kingfisher, Okeene, and Watonga. That is a cap, not a guarantee, and it requires a desuperheater. In Garfield and Major counties, Alfalfa Electric Cooperative pays $1,050 per ton for ground source against $150 per ton for air source.

Paying for it

Financing runs through five partners: Synchrony, Wells Fargo, Wisetack, Klarna, and JB Financing. It covers repairs too.

One Visit Spring or Fall 360, $199. One seasonal visit, no repair discount.
Spring and Fall 360, $360. Two visits, 10% off repairs, two air filters, one installed at each visit.
Full Year 360, $499. 10% off repairs, filters all year with pickup at the office, and the $198 emergency dispatch waived up to twice a plan year, with the $111 diagnostic still charged.

Maintenance plans do not change the geothermal diagnostic. It is $348 flat, any hour. Replacement work is quoted separately before approval.

Where I work

Geothermal is statewide for me: Kingfisher, Okarche, Watonga, Piedmont, Edmond, Enid, Oklahoma City, Lawton, Broken Bow, Durant. Daily service calls stay inside Kingfisher, Canadian, Oklahoma, Garfield, Major, Logan, and Blaine counties. Geothermal does not. Master HVAC license, NATE certified, IGSHPA accredited, and when a job needs a rig I bring in a driller I trust. 4.8 stars, 300+ Google reviews.

Questions people ask me about repairing or replacing geothermal

Is my geothermal worth fixing or should I just replace it?

Depends on what failed and what the loop tests at. One dead component with a healthy loop is a repair. A failed compressor, a leak on the water side of the heat exchanger, or three repairs in one season points to replacement. The verdict goes in writing.

How much does it cost to have my geothermal checked in Kingfisher Oklahoma?

$348 flat, any hour, paid up front. It covers loop pressure, refrigerant charge, desuperheater, controls, and heat exchanger, plus a written report and quote.

What does the $348 geothermal diagnostic include?

The geothermal diagnostic includes testing plus a written report and quote. Replacement work is quoted separately before approval.

Can I keep my existing loop if I replace the geothermal unit?

Often yes, and it is the first thing I test. The loop runs roughly $3,000 per ton, so a replacement reusing a good loop is a very different job than a first install. If it will not hold pressure, you hear that first.

My electric bill jumped and the house will not warm up, is my geothermal failing?

That is the classic pattern of a system leaning on electric backup heat, which runs at COP 1.0 and costs a lot more per Btu than the compressor does. Worth diagnosing.

Is there still a federal tax credit for replacing my geothermal?

The residential credit under Section 25D has expired. Do not budget around it. Commercial projects fall under Section 48. Ask a tax professional, and ask me about utility rebates.

Want a real verdict on your geothermal instead of a guess? Call 405-375-4822. Hartzell’s Heat & Air, 602 S Main St, Kingfisher OK 73750. Also read common geothermal problems and why a loop keeps leaking, or book online.