Sensor tap not working: what to report before a repair

Describe the response precisely

Note whether the tap detects a normal hand movement, shows an indicator, releases water briefly or remains completely unresponsive. If water runs continuously, report that as a separate urgent operating fault rather than repeatedly triggering the sensor. The behaviour of nearby taps helps establish whether the problem is limited to one fitting or affects a shared installation.

Use observations from normal operation rather than prolonged testing. Do not dismantle the spout or expose a control box to find a light. For commercial premises, identify which washroom and basin are affected, how many alternatives remain available and whether the problem changes at particular times of day. A precise location prevents confusion across identical fittings.

The power arrangement is product-specific

Sensor taps may use batteries, a mains-powered unit or another specified arrangement. Bristan and Cistermiser publish model-specific installation and troubleshooting information, so an indicator pattern should be interpreted against the actual product. A flashing light is not a universal battery code, and a replacement power unit must not be selected only because its plug fits.

Where batteries are intended for user replacement, follow the exact accessible user instructions. Leave fixed electrical connections, wet control equipment and unfamiliar enclosures to the appropriate professional. Tell the contractor about recent electrical work or a power interruption, but do not reset protective devices repeatedly or alter wiring to test a suspected supply fault.

A working sensor does not prove the water valve works

The detector and the component controlling water perform different functions. An indicator can respond while another part prevents flow. Conversely, a continuous discharge may involve the control sequence or water valve rather than a sensor that simply failed to notice a user. Diagnosis should follow the complete arrangement instead of replacing the most visible part.

The plumber also needs to consider the local supply, accessible isolation and any specified filters or flow controls. A new restriction after plumbing work is a different clue from a gradual loss of performance. Report recent repairs and product changes. Do not remove a filter or leave a valve bypassed as an informal way to keep the washroom operating.

Check the surroundings and operating mode

The installation position, reflections, objects near the sensor and the intended operating mode can affect behaviour for some products. Describe any changes to mirrors, partitions, soap dispensers or cleaning routines before the fault appeared. The service person should check those conditions against the manufacturer’s instructions rather than assume every unwanted activation is an electronic failure.

Some installations include timed hygiene functions or settings managed centrally. Ask the building team for the product records and commissioning information before calling an unfamiliar cycle a defect. Any adjustment should be made by the appropriate person and recorded, particularly where settings form part of the premises’ water-management arrangements.

Prepare access and approval in an occupied washroom

Controls can be hidden below the basin or inside a service enclosure. Arrange keys and the person authorised to approve isolation or removal of a panel. Keep the affected area out of use if water is escaping or equipment is unsafe. The repair needs an agreed working area, especially where members of the public may otherwise approach the basin.

Cost factors include model identification, diagnostic time, proprietary parts, power arrangements and access. A return visit may be needed when a specific component must be ordered. Agree what facilities remain usable and how temporary restrictions will be communicated. A booked repair is not a reason to leave a continuously flowing or unsafe fitting unattended.

Check the operating cycle after the repair

The completion check should confirm the intended activation and shut-off behaviour, relevant settings and leakage at disturbed joints. Where the fault involved a power or control arrangement, the handover should identify what was changed and whether another trade completed part of the work. A single response to a hand movement is not the whole operational check.

Keep model references, settings changed and parts fitted with the asset record. If the symptom returns, report whether it matches the original sequence and whether the surroundings or usage changed. Consistent records help a maintenance team distinguish recurring hardware failure from an unresolved installation condition or an intentional timed function.

Book a defined sensor-tap investigation

Loyal Plumbers supports commercial plumbing repairs across London and inside the M25. Send the address, tap model, exact symptom and available alternatives in the washroom. Identify the site contact, access restrictions and any existing service records. We can clarify the plumbing and electrical interfaces and arrange the relevant assessment, with photographs shared by email when requested after the enquiry.