Geothermal Loop Purge and Antifreeze Commissioning Inspection

This template covers the field checks needed to confirm a closed-loop ground source heat exchanger is clean, properly purged, correctly charged with antifreeze, and holding pressure before startup. It records circuit-by-circuit flushing, debris removal, concentration verification, leak checks, and final sign-off. It is meant for the loop side of the system, not the heat pump equipment itself.

Use it after loop installation, pressure testing, flushing, and antifreeze charging, but before the loop is connected to the building system for normal operation. It is also useful after major repairs, loop rework, or any event that could introduce air, debris, or concentration changes. If the loop has been opened to atmosphere, re-run the purge and verification steps.

A qualified commissioning technician, HVAC contractor, or mechanical inspector should complete it, with the person verifying purge performance and antifreeze concentration able to interpret the test method used. The signer should be the individual responsible for confirming the loop is ready for service. If local project requirements call for a third-party commissioning agent, this form can support that review.

It is typically performed once during initial commissioning for each geothermal loop system. It should be repeated whenever the loop is drained, reopened, repaired, or recharged in a way that could affect air removal, concentration, or pressure integrity. Some owners also use it as a turnover record for future maintenance reference.

It supports documentation practices commonly expected under mechanical commissioning, owner turnover, and quality control programs, and it can help demonstrate alignment with applicable mechanical codes, manufacturer requirements, and project specifications. For broader safety programs, it also fits well within ISO 9001-style records and contractor quality systems. Final acceptance should always follow the project documents and local authority requirements.

Common issues include incomplete purge of one or more circuits, insufficient flushing velocity, trapped air that later causes noise or poor flow, and antifreeze concentration that does not match the design freeze protection target. It also catches leaks at fittings or headers, pressure loss during the hold period, and missing documentation for the test method used. These are the kinds of deficiencies that can delay startup if they are not corrected before connection.

Yes. You can adapt the circuit count, design minimum temperature, test method, and acceptance fields for vertical bore, horizontal trench, pond loop, or hybrid systems. You can also specify the antifreeze product used, such as glycol or alcohol-based solutions, as long as the project design and manufacturer guidance are followed.

An ad-hoc checklist often misses the details that matter later, such as which circuits were verified, what concentration was measured, and whether the pressure hold was actually completed. This template creates a consistent commissioning record that is easier to review, hand off, and audit. It also gives the owner a clear baseline if performance issues appear after startup.

Yes. It works well in a digital inspection app where photos, notes, signatures, and corrective actions can be attached to each field. Many teams also link it to punch lists, commissioning logs, and closeout packages so deficiencies are tracked through resolution. If you use a CMMS or project management system, the corrective action field can be mapped to a follow-up task.