Description
Zodiac flow detector complete with cable and 3.5 mm connector R0737500
The Zodiac flow detector complete with cable and 3.5 mm connector R0737500 is the original Sika VKL05M flow switch for Zodiac salt chlorinators manufactured before 2017. It monitors water circulation through the hydraulic circuit and signals the control unit to stop chlorine production when the flow is too low, protecting the cell and the installation against dry running.
Characteristics of the Zodiac R0737500 flow detector
- Original Sika VKL05M flow switch assembly for Zodiac salt chlorinators.
- Supplied complete with pre wired cable and 3.5 mm jack connector for direct connection to the control unit.
- Designed specifically for pre 2017 models with 3.5 mm flow detector input.
- Continuously monitors water flow and activates the low flow safety function.
- Replaces the earlier Zodiac reference W197172 that is now discontinued. [oai_citation:0‡poolaria.com](https://www.poolaria.com/recambios-cloradores-salinos/2138-detector-caudal-zodiac-ei-tri-r0737500.html?utm_source=chatgpt.com)
Compatible Zodiac salt chlorinators
The R0737500 complete flow detector with cable and 3.5 mm connector is used across several Zodiac salt chlorination families produced before 2017. It is listed in the Zodiac spare parts catalogue as “detector de caudal completo (+ cable y conector 3,5 mm) antes del 2017”. [oai_citation:1‡recambios.fluidra.com](https://recambios.fluidra.com/es/recambios.php?ownercode=R0737500&utm_source=chatgpt.com)
- Zodiac Ei (W383500, W383510, W383520). [oai_citation:2‡recambios.fluidra.com](https://recambios.fluidra.com/es/recambios.php?ownercode=R0737500&utm_source=chatgpt.com)
- Zodiac Tri and Tri Expert (WW000047, WW000048, WW000049, WW000050). [oai_citation:3‡recambios.fluidra.com](https://recambios.fluidra.com/es/recambios.php?ownercode=R0737500&utm_source=chatgpt.com)
- Zodiac Hydroxinator (WW000005, WW000006, WW000008, WW000009). [oai_citation:4‡recambios.fluidra.com](https://recambios.fluidra.com/es/recambios.php?ownercode=R0737500&utm_source=chatgpt.com)
For later units produced from 2017 onwards, the compatible flow detector is usually Zodiac reference R0792800, which uses a different connection layout, so it is important to confirm the production year and reference of your control unit before ordering. [oai_citation:5‡recambios.fluidra.com](https://recambios.fluidra.com/es/recambios.php?ownercode=R0737500&utm_source=chatgpt.com)
Function and safety role in the system
The flow detector is a safety component that ensures chlorine is only produced when there is sufficient circulation through the cell. It helps protect the hydraulic installation and the cell by preventing electrolysis under no flow conditions.
- Monitors the presence of flow in the return line of the pool. [oai_citation:6‡poolaria.com](https://www.poolaria.com/recambios-cloradores-salinos/2138-detector-caudal-zodiac-ei-tri-r0737500.html?utm_source=chatgpt.com)
- Sends a signal to the control unit to activate the “low flow” or “no flow” protection.
- Interrupts chlorine production automatically when the filtration pump is off or the water level is insufficient.
- Helps prevent overheating of the cell and formation of gas pockets in the pipework.
When to replace the Zodiac R0737500 flow detector
The Sika VKL05M flow switch has moving and electrical parts that can wear over time, especially in water with scale or debris. Typical symptoms that indicate the detector may need replacement include:
- Frequent low flow or no flow alarms despite correct pump operation and open valves.
- Chlorinator does not allow chlorine production even though there is clear circulation through the cell.
- No alarm when the pump stops, suggesting the switch is stuck in a closed position.
- Visible damage, cracks or corrosion on the sensor body, cable or 3.5 mm connector.
Installation guidelines
The Zodiac R0737500 flow detector is typically installed in a saddle clamp or threaded port on the return line near the cell. Replacement is straightforward but should always be done with the hydraulic and electrical system isolated.
- Switch off the filtration pump, close isolation valves and release pressure from the pipework.
- Disconnect the 3.5 mm jack from the control unit and note the cable routing to reproduce a tidy path.
- Unscrew or remove the old flow detector from its fitting and drain any residual water.
- Clean the mounting point and renew the sealing gasket or O ring if required.
- Install the new R0737500 sensor in the same orientation, respecting the indicated flow direction.
- Route the cable back to the control unit, avoiding sharp bends and hot surfaces, and plug in the 3.5 mm connector fully.
After installation, reopen the valves, restart the filtration pump and check the joint for leaks. Then power up the chlorinator and confirm that it correctly detects flow and stops production when the pump is switched off.
Maintenance and good practice
Regular checks of the flow detector help to keep your Zodiac salt chlorinator operating safely and reliably.
- Inspect the sensor periodically for scale, debris and leaks around the fitting.
- In hard water areas, follow the manufacturer guidance to clean the sensor and prevent scale build up on the moving parts.
- Avoid using the detector body as a lever or support when working on nearby pipework.
- Verify correct flow detection at the start of each season by observing the status on the control panel with the pump on and off.
With a correctly installed Zodiac R0737500 flow detector complete with cable and 3.5 mm connector, pre 2017 Ei, Tri, Tri Expert and Hydroxinator systems benefit from reliable low flow protection and safer salt chlorination.
