Common Geothermal Heat Pump Problems and How to Fix Them

When a geothermal system stops heating or cooling correctly, we start by looking at what the equipment is doing. Common geothermal heat pump problems can show up as long run times, weak airflow, auxiliary heat that stays on, or a system that shuts down on a fault. Those details help us narrow the problem to airflow, controls, the circulating pump, or water flow through the ground loop.

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To understand why those parts matter, it helps to know what geothermal heating and cooling is and how the system moves heat. Instead of exchanging heat with outdoor air, geothermal heating and cooling uses a buried ground loop connected to the indoor heat pump.

Suntech has worked with homeowners across the Oklahoma City area since 1986.

The System Runs Constantly but Won't Keep Up

If you are asking, "Why is my geothermal not heating?" start with the thermostat and filter. Make sure the thermostat is set to HEAT, then check for a dirty filter or blocked return.

If those look normal, we check loop flow, the circulating pump, controls, and auxiliary heat operation. Low flow through the heat exchanger reduces how much heat the system can move into the house.

Loop pressure and pump testing are not homeowner checks. Those require the right equipment and readings.

Auxiliary Heat Running Too Often

Auxiliary heat helps when the geothermal heat pump needs extra heating capacity. If it stays on during weather when the geothermal system normally handles the load, we look for the reason.

Low loop flow, airflow problems, control settings, or a heat pump fault can increase auxiliary heat use. Since auxiliary electric heat uses considerably more electricity, a change in the power bill may be the first clue.

Check the thermostat and filter. If auxiliary heat continues running, have the system tested.

Circulating Pump Failures

The circulating pump moves fluid through the ground loop and heat exchanger. If that pump stops or loses flow, the heat pump cannot exchange heat with the ground correctly.

You may notice long run times, weak heating or cooling, or a system that shuts down on a fault.

We check pump operation and flow rate to determine if the problem is the pump, controls, or another part of the loop system. Do not open or work on the pump yourself.

Loop Field Issues

The buried loop field itself can develop problems, but we do not diagnose it from symptoms alone. Air in the loop, incorrect antifreeze concentration, a leak, or another flow problem can affect operation.

Our technicians use pressure and temperature readings to see what is happening through the loop. If the problem is below ground, those readings help us narrow down where further testing is needed.

Loop flushing, pressure adjustments, and antifreeze work belong with a geothermal technician.

Airflow and Filter Problems

Not every geothermal problem starts on the ground loop side. A clogged filter, blocked return, or blower problem reduces the amount of air moving across the indoor coil.

Check the filter and make sure supply registers and returns are open and clear. If airflow remains weak with a clean filter, the blower and indoor equipment need to be checked.

Desuperheater and Hot Water Complaints

Some geothermal systems use a desuperheater to transfer excess heat from the refrigeration cycle to help heat household water. Its contribution changes with how much the geothermal system is running and the operating mode.

If hot water production from the desuperheater changes suddenly, we check the controls, water flow, and geothermal equipment. Do not adjust the desuperheater plumbing or refrigerant system yourself.

Can You Reset a Geothermal Heat Pump?

Start at the thermostat. Make sure it is calling for heating or cooling and check the display for an error message.

If the unit has tripped its breaker and there is no burning smell or visible damage, you can reset the breaker once. If it trips again, leave it off. Repeated trips need diagnosis rather than another reset.

Do not open the geothermal unit to reset internal controls or electrical components.

How Long Should a Geothermal System Last?

The indoor geothermal heat pump and buried ground loop have different service lives. The ground loop is designed to remain in service much longer than the mechanical equipment inside the house.

Maintenance history, installation, water conditions, and equipment use affect the indoor unit's lifespan. If you are deciding between a conventional heat pump and a ground source system, our heat pump vs. geothermal comparison covers the differences between the two.

Geothermal Heat Pump Repair in Oklahoma City

If the filter and thermostat checks do not solve the problem, Suntech can test the loop flow, circulating pump, controls, refrigerant circuit, and other components that require professional diagnosis.

We work on geothermal systems throughout Oklahoma City and in Edmond, Norman, Moore, Yukon, and Mustang. Financing options are available for qualifying work, and the Suntech Club includes annual maintenance for homeowners who want their equipment checked on a regular schedule.