Introduction
This manual provides detailed instructions for the installation, operation, and maintenance of your Timeguard TS900N 24-hour immersion heater timeswitch. Please read this document thoroughly before attempting installation or use to ensure safe and correct operation. Keep this manual for future reference.
Important Safety Information
- Installation should only be carried out by a qualified electrician in accordance with current wiring regulations.
- Always disconnect the mains supply before commencing any installation, maintenance, or wiring work.
- Ensure all electrical connections are secure and correctly wired to prevent electric shock or fire hazards.
- Do not exceed the maximum load rating of 13A (3kW) for this device.
- This device is designed for indoor use only and must not be exposed to moisture or extreme temperatures.
- Do not attempt to modify or repair the unit yourself. Refer all servicing to qualified personnel.
Product Features
The Timeguard TS900N is a reliable 24-hour mechanical timeswitch designed for efficient control of immersion heaters.
- 24-Hour Control: Allows setting of multiple ON/OFF periods over a 24-hour cycle.
- Adjustable Switching Intervals: Features a minimum switching interval of 30 minutes, adjustable in 15-minute steps.
- High Load Capacity: Suitable for resistive loads up to 13 Amperes (3 kilowatts).
- Easy Setting: User-friendly setting pins facilitate straightforward programming.
- Manual Override: Includes a manual override switch for temporary control, bypassing programmed settings.
Package Contents
Please verify that your package contains the following items:
- 1 x Timeguard TS900N Immersion Controller Timeswitch
- 1 x Instruction Manual (this document)
Setup and Installation
Note: Installation must be performed by a qualified electrician and comply with all local and national wiring regulations.
- Preparation: Before beginning, ensure the mains power supply to the immersion heater circuit is completely switched off at the consumer unit (fuse box).
- Mounting: Select a suitable, dry indoor location for the timeswitch, typically near the immersion heater or consumer unit. Secure the timeswitch to the wall using appropriate screws and wall plugs.
- Wiring:
- Connect the incoming Live (L) wire from the mains supply to the terminal marked 'L IN'.
- Connect the incoming Neutral (N) wire from the mains supply to the terminal marked 'N IN'.
- Connect the Earth (E) wire to the Earth terminal.
- Connect the Live (L) wire going to the immersion heater to the terminal marked 'L OUT'.
- Connect the Neutral (N) wire going to the immersion heater to the terminal marked 'N OUT'.
- Secure Connections: Ensure all terminal screws are tightened securely to prevent loose connections and overheating.
- Close Casing: Carefully replace the front cover of the timeswitch, ensuring it is properly seated and secured.
- Power On: Restore mains power supply to the circuit at the consumer unit.

Figure 1: Front view of the Timeguard TS900N Immersion Controller Timeswitch, showing the dial, setting pins, and manual override switch.
Operating Instructions
- Setting the Current Time: Rotate the outer dial clockwise until the current time aligns with the 'TIME' arrow indicator. The dial is marked in 24-hour format (e.g., 13 for 1 PM, 18 for 6 PM).
- Programming ON/OFF Periods:
- The dial's circumference is divided into segments, with each segment representing 15 minutes.
- To set an 'ON' period, push the corresponding segment pins outwards.
- To set an 'OFF' period, ensure the corresponding segment pins are pushed inwards.
- For example, to have the immersion heater ON from 07:00 AM to 08:30 AM, push out all pins between the 07:00 and 08:30 markings on the dial.
- Manual Override: The timeswitch includes a manual override switch, typically a slider or button, with positions such as 'ON', 'AUTO/TIMER', and 'OFF'.
- ON: Keeps the immersion heater continuously ON, overriding any programmed settings.
- AUTO/TIMER: Allows the timeswitch to operate according to the programmed ON/OFF settings. This is the standard operating mode.
- OFF: Keeps the immersion heater continuously OFF, overriding any programmed settings.
Maintenance
- Cleaning: Wipe the exterior of the unit with a soft, dry cloth. Do not use abrasive cleaners, solvents, or wet cloths, as these can damage the unit or cause electrical hazards.
- Inspection: Periodically inspect the timeswitch for any signs of physical damage, loose wiring, or discoloration. If any issues are observed, immediately disconnect power and consult a qualified electrician.
- No User-Serviceable Parts: The internal components of the TS900N are not user-serviceable. Do not attempt to open the unit beyond accessing the wiring terminals during installation.
Troubleshooting
| Problem | Possible Cause | Solution |
|---|---|---|
| Immersion heater not turning ON/OFF as programmed. | Incorrect current time setting; Pins not pushed out/in correctly; Manual override engaged. | Check and adjust the current time setting; Ensure pins are correctly set for desired ON/OFF periods; Set the manual override switch to 'AUTO' or 'TIMER'. |
| No power to the timeswitch. | Mains power supply is off; Loose wiring connection; Blown fuse or tripped circuit breaker. | Check the mains power supply to the circuit; Verify all wiring connections (consult a qualified electrician if unsure); Check the fuse or circuit breaker at the consumer unit. |
| Timeswitch making unusual noises (e.g., grinding, buzzing). | Internal mechanical fault. | Immediately disconnect power to the unit. Do not attempt to repair. Contact a qualified electrician or Timeguard customer support. |
Specifications
- Model: TS900N
- Brand: Timeguard
- Voltage: 230V AC, 50Hz
- Max Load: 13A (3kW resistive)
- Switching Intervals: 30 minutes minimum, adjustable in 15-minute steps
- Material: Plastic
- Color: White
- Product Dimensions (approx.): 19.68"D x 19.68"W x 19.68"H (Note: These dimensions may refer to packaging. Actual unit dimensions are typically smaller.)
- Item Weight: 100 Grams (3.53 ounces)
- Batteries Required: No
- Included Components: Timeswitch unit only.
Warranty and Support
Timeguard products are designed for reliability and performance. For specific warranty terms and conditions, please refer to the official Timeguard website or the warranty card included with your purchase. Keep your proof of purchase for any warranty claims.
For technical assistance, troubleshooting beyond this manual, or to inquire about spare parts, please contact Timeguard customer support.
Timeguard Contact Information:
- Website: www.timeguard.com
- Customer Service: Refer to the website for regional contact details and support options.