Hydronic System Glycol Concentration and pH Log

This template is for closed hydronic heating loops and chilled water loops that use glycol and corrosion inhibitor. It fits boiler plants, fan coil systems, process cooling loops, and other sealed water circuits where freeze protection and water chemistry matter. It is not meant for open cooling towers or unrelated maintenance logs.

Use it on the cadence that matches your plant risk and service plan, such as weekly, monthly, or after any makeup water addition. Systems with higher leak risk, seasonal freeze exposure, or tighter water-quality requirements usually need more frequent checks. The key is to keep the recurrence consistent so trends are visible.

The DRI is usually a facilities technician, HVAC mechanic, building engineer, or water-treatment vendor, depending on who services the loop. The person completing it should know how to take a refractometer reading, read pH correctly, and record whether any action is blocking or non-blocking. Supervisors can review the log for trend changes and follow-up.

It helps catch low glycol concentration, drifting pH, depleted inhibitor, and unexplained makeup water additions before they lead to freeze damage, corrosion, pump wear, or heat-transfer problems. The log also creates a clear record when a loop starts consuming water, which is often the first sign of a leak or maintenance issue. It is a monitoring tool, not a repair work order.

Yes, it supports maintenance documentation and demonstrates that the loop is being monitored on a defined recurrence. While it is not a standalone regulatory form, it can help show due diligence for equipment reliability, safety, and preventive maintenance. If your site follows a water-treatment program, this log can be part of that record set.

Common mistakes include recording only glycol percentage without pH, skipping the verification step after adding makeup water, and treating every reading as critical. Another frequent issue is mixing up test methods or using an uncalibrated refractometer, which makes the trend data unreliable. The log works best when each checklist item is independently verifiable.

Yes, you can add fields for loop name, test temperature, inhibitor brand, sample point, or corrective action notes. Many teams also add a blocking flag for readings outside target range and a follow-up task for water treatment or leak investigation. Keep the core items simple so the log stays easy to complete during routine rounds.

An ad-hoc note often captures one reading but misses the trend, the follow-up, or the reason for a makeup water addition. This template standardizes the checklist item order, makes the data easier to review, and helps different technicians record the same information the same way. That consistency is what turns a reading into a usable maintenance record.