Hayward - ORP / RX Replacement Probe - GLX-PROBE-ORP

Hayward – ORP / RX Replacement Probe – GLX-PROBE-ORP

The Hayward GLX-PROBE-ORP is the genuine OEM replacement oxidation-reduction potential (ORP) sensor for Hayward AquaRite Pro and Sense and Dispense control systems. As with all genuine Hayward sensors, this probe is electrically and mechanically identical to the factory-fitted original, guaranteeing that its output voltage range and response characteristics are fully matched to the controller’s input specification. An aftermarket ORP sensor with a different reference electrode potential or output impedance can cause persistent calibration offset or control instability — problems that are eliminated by fitting this genuine replacement.

What ORP Measures and Why It Is the Definitive Disinfection Indicator

ORP — oxidation-reduction potential — is measured in millivolts and represents the electrochemical potential of the pool water to oxidise and destroy contaminants. Unlike a simple chlorine concentration measurement, ORP reflects the actual disinfecting power available in the water at that moment, taking into account pH, temperature, cyanuric acid level, and the ratio of active to combined chlorine. A pool water ORP value above 650–700 mV indicates highly effective disinfection; values below 600 mV suggest insufficient sanitiser activity regardless of the total chlorine reading. By feeding this real-time ORP value into the AquaRite Pro controller, the system can modulate chlorine dosing or electrolysis output continuously and automatically, maintaining safe, well-sanitised water without the cost and chemical waste of chronic over-dosing.

Direct-Fit Replacement for Hayward Flow Cell Installations

The GLX-PROBE-ORP connects via a standard BNC connector and fits directly into the ORP sensor port in your Hayward bypass assembly or flow cell housing without any modifications, adapters, or rewiring. It is compatible with the full range of AquaRite Pro and Sense and Dispense installations, including those paired with Hayward salt chlorinators and conventional chemical dosing systems. The probe body is designed for permanent immersion in pool water and is resistant to the chemical environment of both chlorinated and salt-treated pools. The compact 21 × 9 × 6 cm form factor ensures it fits in all standard Hayward sensor housings without clearance issues.

Recognising When Your ORP Probe Has Reached End of Life

ORP sensors degrade gradually as the platinum working electrode becomes fouled with metal oxides, biofilm, or scale, and as the reference electrode’s internal electrolyte becomes depleted. The most reliable indicators that replacement is needed are: readings that no longer correspond to the actual sanitation state of the water (verified by independent ORP meter or DPD test); a controller that alarms repeatedly on low ORP despite adequate chlorine levels; readings that are stable but consistently offset from the expected value; and a probe that cannot be brought back into calibration range by cleaning alone. Timely replacement is important — a faulty ORP probe can lead the controller to under-dose (creating a health risk) or over-dose (creating excess chemical costs and swimmer discomfort).

Installation, Calibration and Long-Term Maintenance

After installing the GLX-PROBE-ORP, allow a stabilisation period of 15–30 minutes before calibrating against a certified ORP reference solution — Zobell solution (220 mV at 25 °C) or a 465 mV quinhydrone standard are the most commonly used references for pool sensors. Verify the reading against the reference and adjust the controller offset as needed. During operation, periodically inspect the probe tip for scale or fouling and clean gently with a lint-free cloth moistened in dilute hydrochloric acid (1–5%) or a proprietary electrode cleaner if deposits are present. At the end of the season, store the probe in electrode storage solution to preserve the reference junction and extend service life into the following year.