If you live on Vancouver Island, you’ve probably noticed that geothermal (or geoexchange) heating and cooling is becoming increasingly popular. From custom oceanfront builds in Queenswood to acreages out in Metchosin and the Highlands, more homeowners are moving away from fossil fuels and conventional outdoor heat pumps in favour of the earth itself, and it makes sense.
While standard air-source heat pumps have to fight through salt air, heavy winter rains, and freezing coastal winds, a geothermal system keeps its mechanical equipment safely inside, while its outdoor loops sit protected deep underground.
Because of that built-in protection, a quality geothermal system is an incredible long-term investment. The indoor heat pump typically lasts 20 to 25 years, and the underground loop field is engineered to last 50 years or more. But like any high-performance system, “long-lasting” doesn’t mean “maintenance-free.”
Here is a look at how geothermal heating actually works on Vancouver Island, what ongoing maintenance looks like, and how to get the best performance out of your system.
Geothermal 101: Tapping Into the Earth
To understand how to maintain a geothermal system, it helps to know how it operates under the hood. Regardless of what the weather is doing above ground, the earth just a few feet below the surface in Greater Victoria stays at a constant, steady temperature of roughly 10°C to 12°C year-round. Geothermal systems use that stable temperature as a thermal battery:
- In the winter, fluid circulates through an underground loop of pipes, absorbing heat from the earth. The indoor heat pump compresses that low-grade heat into high-temperature heat and distributes it through your home’s ductwork or radiant floor loops.
- In the summer, the process simply runs in reverse. The system pulls warm air out of your home and rejects that excess heat back into the cooler ground.
Because the system doesn’t have to create heat (it just moves it around) it can achieve efficiency ratings of 400% to 500%. That means for every $1 of electricity you put into the system, you get $4 to $5 worth of heating or cooling out, compared to traditional electric heating systems.
The 4 Main Types of Geothermal Loops on Vancouver Island
Depending on where you live on the South Island, your system will rely on one of four main loop designs:
- Vertical Closed Loops:
- The most common choice for compact residential lots in Victoria, Oak Bay, and Saanich. We drill boreholes deep into the underlying bedrock to run closed loops vertically.
- Horizontal Trench Loops:
- Popular on acreages and larger properties where there is plenty of land to bury loops a few feet below the frost line without deep drilling.
- Pond, Lake & Ocean Loops:
- For coastal or waterfront properties, sealed loop lines can be submerged in water, using the ocean or a pond as an endlessly renewable heat sink.
- Open-Loop Well Systems:
- Where local groundwater aquifers allow, clean well water is drawn directly through the heat exchanger and returned safely to the earth.
What Does Geothermal Maintenance Actually Involve?
Because your exterior loops are buried and your main heat pump is sitting comfortably in your mechanical room, you don’t have to worry about cleaning weather-beaten outdoor coils or clearing away fallen branches.
Instead, geothermal servicing is specialized mechanical work focused on hydronics, chemistry, refrigeration, and electrical performance.
1. Loop Chemistry & Antifreeze Health
The fluid running through your underground loops (usually a mixture of water and environmentally safe propylene glycol or methanol) is the lifeblood of the system. Over years of service, this fluid needs to be tested for:
- pH Balance & Acid Level:
- Degraded fluid can become acidic over time, which can slowly corrode internal heat exchangers.
- Freeze Protection:
- We check the antifreeze concentration with a digital refractometer to ensure the fluid won’t slush or freeze during peak winter heating cycles.
- System Pressure:
- We check loop pressure and inspect flow centers to confirm there are no micro-leaks or pressure drops over time.
2. The Hidden Risk of Air Locks—and Why System Flushes Matter
One of the most critical parts of geothermal maintenance is managing what’s happening inside those underground pipes. Even in a sealed closed-loop system, air pockets and micro-debris can become a serious problem over time.
When air bubbles get trapped inside the loop piping, they combine to create an air lock. Because water always takes the path of least resistance, an air lock can completely block fluid circulation through one or more of your earth boreholes.
- The warning signs:
- You might hear loud gurgling, swishing, or rushing-water sounds coming from the pipes in your mechanical room.
- The risk:
- When fluid can’t flow properly, the heat pump can’t extract enough heat from the ground. Your compressor has to work overtime, safety sensors can trigger system lockouts, and your heating can silently fall back onto expensive backup electric resistance heat.
- The solution (Geothermal Flushing):
- You can’t clear a geothermal air lock with a standard residential water pump—the pipes are simply too long and deep. If air locks, sediment, or degraded antifreeze are detected, our technicians connect a specialized, high-velocity geothermal flush cart to your loop ports. This powerful rig blasts fluid through the underground pipes at high gallons-per-minute (GPM) rates, purging every trapped air bubble, filtering out pipe scale, and restoring your loop to factory-clean flow.
3. Hydronic Flow & Circulator Pumps
A geothermal heat pump relies on steady water flow to transfer energy. We measure temperature differentials (Delta-T) between the fluid entering and leaving the machine. By checking pump performance alongside loop pressure, we make sure the earth loop is absorbing heat at peak efficiency without stressing your circulator pumps.
4. Electrical & Refrigeration Diagnostics
This is where working with a full-service geothermal and mechanical contractor matters. A comprehensive maintenance includes the following and more:
- Testing compressor and blower motor amp draws to catch wearing bearings early.
- Inspecting and tightening high-voltage electrical connections and relay contacts.
- Calibrating thermostats and verifying that refrigeration superheat and subcooling levels match factory specifications.
Homeowner Checklist: What You Can Do Between Services
While technical diagnostics should be left to a licensed professional, there are three easy ways you can protect your system year-round:
- Check Your Air Filters Bi-Monthly:
- Restricted airflow is the single most common cause of heat pump inefficiency and system lockouts. Replace or wash your filters every 2 months.
- Keep an Eye on Your Hydro Bills:
- Geothermal issues can be subtle. If your loop circulation slows down due to an air lock or pressure drop, your system may automatically fall back on backup electric resistance heat. Your house will still feel warm, but your electricity bill will jump.
- Listen to Your Mechanical Room:
- Geothermal heat pumps are famously quiet. If you suddenly hear gurgling or swishing noises in your pipes, don’t ignore it, it’s the classic sign that air has entered the closed loop and a system flush or pressure check is needed.
Built on Trust, Backed by Experience
At Primera, we take pride in doing things the right way. Geothermal heating and cooling is a specialized trade and iit requires a deep understanding of refrigeration, hydronics, loop hydraulics, and electrical systems all working together in harmony.
Whether we installed your geothermal system from scratch or you have an existing system that needs troubleshooting, flushing, and ongoing care, our team has the training and specialized equipment to keep it running smoothly.
Have questions about your geothermal system, hearing gurgling pipes, or ready to book your annual maintenance?
Reach out to our office today. We’re here to help you get the most out of your home’s heating and cooling.
