The Isolation-First Approach
A geothermal pool heating system connects to the pool plumbing at the equipment pad, typically through a heat exchanger where pool water passes through a component heated or cooled by the ground loop system. That connection creates two diagnostic questions: is the pool itself losing water, or is the heating system involved in the loss?
Answering that question requires testing each side with the other isolated when safely possible.
Account for heat-related evaporation first
Heated pool water evaporates faster than ambient-temperature water. Before concluding a geothermal-heated pool is leaking, confirm that the water loss rate exceeds what evaporation from a heated pool would reasonably explain. A bucket test with heated water provides the comparison baseline specific to that pool's conditions.
Isolate the geothermal system from the pool
If the system can be safely valved off from the pool circuit, observe pool water loss with the geothermal system bypassed. If water loss changes significantly when the system is isolated, that points toward the geothermal connection. If loss continues at the same rate with the system bypassed, the loss is likely in the pool itself or standard pool plumbing.
Inspect visible connections and equipment
Check the heat exchanger connections, bypass valves, unions, fittings, and any visible plumbing where the geothermal system ties into the pool circuit. Leak indicators at connection points - corrosion, mineral deposits, wet areas, dripping - can be identified visually before any pressure testing is applied.
Evaluate standard pool components normally
The pool shell, fittings, lights, skimmers, plumbing lines, and equipment pad components are all tested using standard methods regardless of the heating system type. The geothermal connection does not change how pool pressure testing, dye work, or structural evaluation is performed.
Refer the geothermal unit if it appears involved
If testing indicates the loss is tied to the geothermal unit, heat exchanger, or sub-surface ground loop, that component needs a qualified geothermal, HVAC, or mechanical professional - not a pool leak technician. Document the finding and the referral clearly.
This is not a place to guess. A geothermal system that appears to be leaking into the pool circuit, or that appears to be losing water from the ground loop side, involves mechanical and refrigeration engineering considerations that go well beyond pool leak detection scope. Document what the isolation testing shows and refer the rest.
Learn to Test Connected Systems Systematically
LBA teaches isolation-first evaluation of connected pool systems - so findings are grounded in what the testing showed, not what was assumed.
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