Hayward CAT 4000 (W3CAT4000WIFI) is an NSF/ANSI 50 certified commercial water chemistry controller with Wi-Fi. Continuously monitors and controls ORP and pH for automated sanitizer and acid dosing. Wireless remote monitoring via PoolComm for 24/7 access from any device. Includes pH and ORP sensors, flow cell, flow switch, PVC backboard, back-up sanitizer relay, and one aux relay. 5-year warranty on controller; 2-year on sensors.
- SKU: W3CAT4000WIFI
- 5-year limited warranty on controller; 2-year limited warranty on sensors
- NSF/ANSI Standard 50 certified
- Continuous ORP and pH monitoring with automatic chemical feed control
- Wi-Fi connected; links to PoolComm for remote monitoring, alarm notifications (email, SMS, visual, audible), and data logging from any web device
- PoolComm is a subscription service; monthly charges apply
- View water quality data, print charts, analyze graphs, and change controller settings remotely
- Dual sanitizer setpoints for back-up ORP control
- One auxiliary relay for additional control versatility
- Compatible with all types of chemical feed equipment
- Includes: pH sensor, ORP sensor, machined flow cell and rotary flow sensor, flow switch, PVC backboard
- Flow switch interlock suspends dosing when circulation stops
- NEMA 4X enclosure for equipment room and mechanical space installation
- One controller per pool or independent circulation system
Hayward CAT 4000 Commercial Water Chemistry Controller (W3CAT4000WIFI): Automated ORP and pH Management
The CAT 4000 continuously samples ORP and pH from flow-cell sensors in the pool circulation stream and activates chemical feed pumps automatically to hold both parameters within programmed setpoints. No hourly manual testing required. Wi-Fi connects the controller to PoolComm so facility managers can monitor water chemistry, receive alarms, and adjust settings remotely from any internet-connected device around the clock. The professional package includes all sensors, flow cell, flow switch, and backboard for complete out-of-box installation.
Why the CAT 4000 Controls to ORP, Not Calculated Free Chlorine
ORP measures the water’s actual electrochemical oxidizing capacity, not a theoretical chlorine demand calculation. At the same free chlorine concentration, ORP varies significantly with pH, combined chlorine levels, temperature, and stabilizer. Controlling to ORP gives the CAT 4000 a direct, real-time relationship with actual sanitation effectiveness, which is why ORP-based control is the commercial aquatic industry standard. pH control runs in parallel for coordinated acid dosing.
Hayward CAT 4000 Water Chemistry Controller Specifications
SKUW3CAT4000WIFI CertificationNSF/ANSI Standard 50 Listed Control ParametersORP (mV) and pH ORP Range0 to 1000 mV pH Range0 to 14 ConnectivityBuilt-in Wi-Fi; remote access via PoolComm (subscription required) Alarm FormatsEmail, SMS, visual, audible Relay OutputsORP chemical feed, pH chemical feed, back-up sanitizer, (1) auxiliary relay Safety InterlockFlow switch input; suspends dosing when flow stops DisplayBacklit LCD; real-time ORP, pH, and status Data LoggingYes; exportable for regulatory compliance documentation EnclosureNEMA 4X (watertight, corrosion-resistant) Power120V / 240V dual voltage IncludespH and ORP sensors, machined flow cell, rotary flow sensor, flow switch, PVC backboard ApplicationCommercial pools, aquatic centers, water parks, splash pads; one unit per pool Warranty5-year limited (controller); 2-year limited (sensors)ORP and pH setpoints must meet or exceed the minimums specified by your applicable state or local health code. Setpoint programming should be completed in collaboration with a certified pool operator (CPO) or aquatic facility consultant. The CAT 4000 is a control and monitoring tool, not a substitute for qualified operator oversight.
Frequently Asked Questions
How many pools can one CAT 4000 manage?
One. Each CAT 4000 manages one pool or one independent circulation system. Multi-pool facilities require one unit per pool. All units at a facility can be monitored from the same PoolComm dashboard, but each operates independently.
Is PoolComm remote monitoring included or a separate subscription?
PoolComm is a subscription-based service with monthly charges. The controller includes the Wi-Fi hardware to connect to it, but the monitoring service itself is billed separately.
Is the CAT 4000 compatible with salt chlorination systems?
Yes. The CAT 4000 can work with salt chlorination as the oxidizer source. The ORP sensor monitors sanitizer output, and the controller can modulate the cell or trigger supplemental dosing. Confirm integration compatibility with the specific salt system being used before installation, as integration methods vary by manufacturer.
What ORP setpoint should be programmed?
The setpoint must meet or exceed your jurisdiction’s regulatory minimum, commonly 650 mV for stabilized pools or 720 mV or higher for unstabilized pools. Because ORP drops as pH rises and combined chlorine builds, program a safety margin above the regulatory minimum. Consult a CPO or aquatic facility consultant for your specific facility conditions.
Hayward CAT 4000 Water Chemistry Controller Manual and Warranty Info
- Owner’s Manual (PDF)
- Installation and Setup Guide (PDF)
