Geothermal System Troubleshooting & Seasonal Tips
Before requesting a service visit, please try the steps below — many issues can be resolved in just a few minutes. If your system still isn’t working properly after these steps, contact us and we’ll be glad to help.
General Troubleshooting Steps
Try these steps any time you notice your system isn’t heating or cooling as expected.
1. Which unit is affected?
If you have more than one heat pump, make a note of which system (or systems) is having trouble — for example, the upstairs unit or the unit serving the main floor. This helps us assist you faster if a service visit is needed.
2. Check your air filter
A dirty filter restricts airflow and forces your system to work harder. We recommend checking filters every 30 days during peak heating or cooling season, and replacing or cleaning them every 60–90 days — more often if you have pets, dust, or recent construction.
3. Check your thermostat settings
Make sure all thermostats are secured to the wall, in their base, and set to the correct mode — Heat or Cool (not Auto). We recommend switching modes manually at the start of each season rather than relying on Auto. If you have multiple zones or thermostats, make sure they’re all set to the same mode — a single thermostat left in the wrong mode can prevent the rest of the system from running properly.
Is the system reaching your set temperature? If not, note what it’s currently set to and what temperature it’s displaying — this detail is helpful if you end up requesting service.
4. Check your vents
Make sure all supply and return vents are open and unobstructed by furniture, rugs, or curtains.
5. Check your condensate pump (cooling season)
In cooling mode, your system removes humidity from the air and drains it away. Confirm the area around your air handler is dry. If you have a condensate pump, make sure it’s plugged in and that the GFCI outlet it’s connected to hasn’t tripped (press the reset button if needed). You can also test the pump by pouring a small cup of water into the reservoir — it should kick on and drain promptly. A failed condensate pump can trigger a system lockout.
6. Power cycle your system
A reset can clear fault codes and restore normal operation, especially after a power outage or surge.
- At your main breaker panel, turn off all breakers for the affected system. (Split systems typically have two breakers — one for the compressor and one for the air handler; package units usually have one main breaker.)
- Wait at least 5 minutes. This is a good time to check or swap your air filter.
- Turn the breakers back on and allow the system 15–20 minutes to fully restart.
Extreme Heat: Tips to Keep Your Home Cool
Your geothermal system is well-suited for extreme heat — unlike a conventional air conditioner, it doesn’t have to work against hot outdoor air. Instead, it uses the earth’s naturally stable underground temperature to cool your home efficiently, even when it’s sweltering outside. A few simple steps will help it perform at its best during a heat wave.
Thermostat settings
- Set it and leave it. Pick a comfortable setpoint — 75°F is our recommended target — and avoid adjusting it throughout the day. Geothermal systems run most efficiently holding a steady temperature. Turning the system off while you’re out and cranking it back down when you return puts far more strain on the unit than simply maintaining a consistent setpoint.
- Make sure every thermostat in your home is set to Cool. If you have multiple zones or heat pumps, every thermostat needs to be in Cool mode — one left in Heat or Auto can prevent the rest of the system from cooling properly.
Reduce heat gain in your home
- Close your blinds and curtains from late morning through early evening, especially on south- and west-facing windows. Blocking direct sunlight is one of the most effective ways to reduce your home’s cooling load.
- Run the oven, dryer, and dishwasher in the evening or early morning. These appliances generate significant heat. If possible, grill outside or opt for cold meals on the hottest days.
- Make sure all supply and return vents are open and unobstructed. Blocked vents increase pressure and reduce how effectively cool air reaches each room.
- Ceiling fans help. Set them to run counter-clockwise (summer mode) to push air downward. This can make a room feel several degrees cooler without adjusting your setpoint.
Quick checks before a heat wave hits
- Change your air filter. A dirty filter restricts airflow and forces the system to work harder. If it hasn’t been changed since heating season, replace it now.
- Check your condensate pump. Confirm the area around your air handler is dry, that the pump is plugged in, and that its GFCI outlet hasn’t tripped (press the reset button if needed). Test the pump by pouring a small cup of water into the reservoir — it should kick on and drain promptly. A failed condensate pump can trigger a system lockout.
- If your system isn’t cooling, try a power cycle first. Turn the breaker off, wait a full 5 minutes, then turn it back on. This clears most fault codes without requiring a service visit.
Extreme Cold: Tips to Keep Your Home Warm
During periods of colder-than-usual outdoor temperatures, it’s normal for geothermal systems to work harder to maintain indoor comfort. You may notice your thermostat running a few degrees below the set point or increased use of auxiliary (aux) heat. Aux heat is designed to provide a boost during higher demand and does not automatically indicate a problem.
Geothermal systems are designed around typical winter conditions, so when temperatures drop well below average, they may not always keep up with higher set points as easily. To help your system run more efficiently:
Thermostat settings
- Consider slightly lowering your thermostat set point on the coldest days. Our recommended setpoint is 70°F — every degree above that can meaningfully increase aux heat use and your electric bill on very cold days.
- Keep a steady temperature day and night. Avoid frequent adjustments — geothermal systems perform best maintaining a consistent setpoint rather than recovering from large swings.
- Make sure every thermostat in your home is set to Heat (not Auto).
- If you use setbacks, keep them modest — no more than 3°F below your usual setpoint — and pair them with a set schedule and Smart Recovery enabled, so the system can recover gradually without relying on aux heat.
- Reverse your ceiling fans. Set them to run clockwise (winter mode) at a low speed. This gently pulls cool air up and pushes the warm air that collects near the ceiling back down into the room, helping the space feel warmer without raising your setpoint.
Quick checks before extreme cold hits
- Check and replace or clean your air filter. Filters should be checked monthly during heavy heating use — a dirty filter can significantly reduce system performance.
- Make sure all vents are open and unobstructed.
- If you’ve recently had a power outage or surge, a power cycle can often resolve the issue: turn off your system’s breakers at the main panel, wait 5 minutes, then turn them back on and allow 15–20 minutes for the system to restart.
Still Need Help?
If you’ve worked through the steps above and your system still isn’t performing as expected, we’re happy to help.
- Email us at support@dandelionenergy.com
- Call us at (833) 436-4255 — for emergencies outside of business hours, please call so we can assist you right away.
Curious about our service plans, or standard and out-of-service-territory (OST) pricing for a visit? Visit our Service Plans page or our Service Pricing page for details.