How to Install & Maintain a Sensor Tap: The Complete Guide

Sensor taps — also known as automatic taps or touchless taps — are becoming increasingly popular in both domestic and commercial settings across the UK. Whether you're upgrading a bathroom, fitting out a commercial washroom, or replacing a faulty component, this guide walks you through everything you need to know about sensor tap installation and maintenance.

Why Choose a Sensor Tap?

Infrared sensor taps offer a range of benefits over traditional manual taps:

• Improved hygiene — no cross-contamination from touching handles
• Water savings — water only flows when hands are detected, reducing waste
• Convenience — ideal for users with limited mobility
• Modern aesthetics — a clean, contemporary look for any washroom

They're a smart investment for homeowners and facilities managers alike.

Understanding the Key Components

Before you begin any installation or repair, it helps to understand how a sensor tap system works. Most automatic tap setups consist of three core components:

1. The Control Box

The control box is the brain of the system. It processes the signal from the infrared sensor and triggers the solenoid valve to open or close. Our AS1CB and AS2CB sensor tap control boxes are compatible with a wide range of tap bodies and are designed for straightforward installation.

2. The Infrared Sensor Module

The sensor module detects the presence of hands beneath the tap. It emits an infrared beam and, when that beam is broken by a hand, sends a signal to the control box. We stock several sensor modules — the ASM1, ASM2, and ASM3 — to suit different tap designs and mounting configurations.

3. The Solenoid Valve

The solenoid valve controls the flow of water. When the control box receives a signal from the sensor, it opens the valve; when hands are removed, it closes again. Our ASV1-6V pulse solenoid valve is engineered for reliability and low power consumption, making it ideal for battery-operated systems.

Power Options: Mains vs. Battery

Sensor taps can be powered by mains electricity or batteries. Battery-powered systems are popular where mains wiring isn't accessible. If you're using a battery-powered setup, choosing the right battery box is essential.

We offer three battery box options to suit different tap connectors:

• AS-BB1 — round connector
• AS-BB2 — flat connector
• AS-BB3 — jack connector

Check your existing tap or control box connector type before ordering to ensure compatibility.

Step-by-Step: Installing a Sensor Tap Control Box

If you're replacing a faulty control box or fitting a new sensor tap system, follow these steps:

1. Turn off the water supply — isolate the hot and cold feeds beneath the basin.
2. Disconnect the old control box — unplug the sensor module and solenoid valve connectors, then remove the unit.
3. Connect the new control box — plug in the sensor module and solenoid valve to the corresponding ports on the new unit (refer to the wiring diagram supplied).
4. Connect the power source — attach your battery box or mains transformer as appropriate.
5. Restore the water supply — slowly turn the isolation valves back on and check for leaks.
6. Test the sensor — pass your hand beneath the tap to confirm the sensor triggers correctly and water flows and stops as expected.

How to Replace a Faulty Infrared Sensor Module

If your tap is no longer detecting hands reliably, the sensor module is often the culprit. Here's how to replace it:

1. Disconnect the sensor module cable from the control box.
2. Unscrew or unclip the sensor from the tap spout or body.
3. Fit the replacement sensor module (e.g. ASM1, ASM2, or ASM3 depending on your tap model) and secure it in place.
4. Reconnect the cable to the control box.
5. Test the tap — the sensor should now respond promptly to hand movement.

Tip: Before replacing the sensor, check that the lens is clean and free from limescale or soap residue, as build-up can interfere with detection.

Routine Maintenance Tips

Keeping your sensor tap in good working order doesn't require much effort. Follow these simple maintenance steps:

• Clean the sensor lens regularly — use a damp cloth to remove limescale and soap deposits. Avoid abrasive cleaners.
• Check battery levels — most battery-powered systems will give a low-battery warning (often a slow or intermittent flow). Replace batteries promptly to avoid complete failure.
• Inspect the solenoid valve — if the tap drips when not in use, the solenoid valve may need cleaning or replacing.
• Check water temperature — if your system includes a thermostatic mixing valve (such as our ATV1-12F), check the temperature setting periodically to ensure it remains within safe limits (typically 38°C for handwashing).
• Descale internal components — in hard water areas, limescale can build up inside valves and restrict flow. Annual descaling is recommended.

Troubleshooting Common Sensor Tap Problems

Here are some of the most common issues and their likely causes:

• Tap not activating — check battery level, sensor module connection, and ensure the sensor lens is clean.
• Tap running continuously — the sensor may be detecting a false trigger (e.g. a reflective surface nearby). Reposition the tap or adjust the sensor range if possible.
• Weak water flow — check for limescale blockage in the solenoid valve or aerator.
• Tap dripping after use — the solenoid valve may be worn or contaminated. Inspect and replace if necessary.
• Intermittent operation — low batteries or a loose sensor connection are the most common causes.

Need Replacement Parts?

Auto Sensor stocks a comprehensive range of sensor tap components, including control boxes, infrared sensor modules, solenoid valves, battery boxes, thermostatic mixing valves, and soap dispensers. Whether you're carrying out a repair or a full installation, you'll find the parts you need in our online store.

If you're unsure which component is right for your tap, feel free to get in touch — we're happy to help you find the correct replacement.