# Timeguard NTT03 24-hour/7-day immersion heater timeswitch

Timeguard NTT03 is a compact electronic timeswitch for domestic immersion heaters, with daily or weekly scheduling and short boost controls. Its programme flexibility and power-cut clock backup suit households with changing hot-water routines, while installation is recommended for a qualified electrician.

- [Original product page](https://bargainpostbox.co.uk/product/timeguard-ntt03-immersion-heater-timeswitch)
- [View offer](https://bargainpostbox.co.uk/visit/timeguard-ntt03-immersion-heater-timeswitch)
- Market: UK
- Language: en-GB
- Currency: GBP
- Brand: Timeguard
- Model: NTT03
- Category: Tools & Garden > Electrical & Plumbing
- Price: 31.15 GBP
- Previous price: 34.99 GBP
- Discount: 11%
- Price checked: 2026-11-12T17:40:04.389Z
- Rating: 4.3 / 5
- Reviews: 1366

Prices and deal status are the latest recorded data, not a guarantee of availability. Confirm the price and availability with the store.

## At a glance

- Set up to four on/off periods per day, with the same schedule every day, a weekday/weekend split or separate daily programmes.
- A one- or two-hour boost is available at the button, and advance/override controls can skip to the next programme or hold output on or off.
- The built-in rechargeable battery is claimed to preserve the clock and programmes during a power cut.
- Programme review, an illuminated screen and power/output LEDs make settings and output status easier to check.

## Pros

- Flexible weekly scheduling supports routines that vary between weekdays and weekends.
- Short boost options provide a timed way to add hot water without changing the regular schedule.
- Power-cut clock and programme backup reduces the need to re-enter settings after an interruption.

## Cons

- Installation is recommended to be carried out by a qualified electrician, so this is not presented as a simple plug-in timer.

## Specifications

### Identity
- Brand: Timeguard
- Model: NTT03
### Programming and operation
- Scheduling: 24-Hour/7-Day
- Daily programme periods: 4 ON/OFF periods per day
- Schedule options: every day the same, weekdays and weekends separately \(5+2\), or each day individually
- Switching interval: accurate to the minute
- Output rating: 16A resistive loads
- Clock backup: A built-in rechargeable battery keeps the clock running and your programmes saved during a power cut.
- Automatic seasonal time change: Optional automatic summer/winter time changeover
- Display and indicators: illuminated screen and power and output LEDs
- Control output: Digital
- Maximum time: 168H
### Electrical
- Voltage: 230 Volts
### Dimensions and installation
- Dimensions listed: 11.7 x 16.9 x 23.2 cm; 171.1 g
- Weight listed: 171 g
- Wall box fit: single gang wall box with a minimum depth of 32mm
### Materials and protection
- Material listed: Plastic

## Before you buy

- The listing says the timer is not suitable for discharge lighting. Confirm the existing wall box and installation requirements with a qualified electrician before fitting.

## A good fit for

- Households using a domestic immersion heater that want recurring weekday, weekend or day-by-day schedules.
- Buyers who want timed boost and advance/override controls alongside a regular programme.

## Less suited to

- Anyone seeking a plug-in timer or a product described as suitable for discharge lighting.

## Customer feedback

The aggregate ratings lean positive, with a majority in the five-star category, but a smaller share of ratings are low. Ratings alone do not explain why customers scored it that way. For buyers considering its stated weekly scheduling and boost controls, the figures offer a broad satisfaction signal rather than evidence about installation ease or performance in a particular setup.

## Frequently asked questions

### Can the NTT03 use different schedules on different days?
The listing describes four on/off periods per day and allows a repeated daily schedule, a weekday/weekend split or individual programmes for each day.
### How does the boost function work?
The listing describes a one-hour boost with one press and a two-hour boost with two presses, after which the heater switches off automatically.
### Does it retain its settings during a power cut?
The listing claims its built-in rechargeable battery keeps the clock running and programmes saved during a power cut.
### Is professional installation recommended?
Yes. The listing recommends installation by a qualified electrician and says the timer fits a single gang wall box with a minimum depth of 32mm.

## Alternative options

- [Timeguard TW1001 Smart WiFi Fused Spur Switch, Immersion Heater Timer \| 2.4GHz & 5GHz Smart Switch, 13A Double Pole Timeswitch, App Control with Boost, Countdown & ON/OFF, Alexa & Google Compatible](https://bargainpostbox.co.uk/visit/timeguard-tw1001-smart-wifi-fused-spur-timer)
- [Digital Programmable Switched Fused Spur Timer](https://bargainpostbox.co.uk/visit/timeguard-ntt03-immersion-heater-timeswitch)
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- [Normodic Smart Immersion Heater Timer Switch 40A 8000W, WiFi Water Heater & Boiler Controller, APP Remote Control, Touch Wall Switch, Compatible with Alexa Google Home, Schedule Timer](https://bargainpostbox.co.uk/visit/timeguard-ntt03-immersion-heater-timeswitch)
- [HBN 24 Hour Indoor Energy Saving Mechanical Immersion Heater Segment Timer Switch with Waterproof Cover, White, 16 Amps](https://bargainpostbox.co.uk/visit/timeguard-ntt03-immersion-heater-timeswitch)
- [Smart WiFi Fused Spur Timer Switch for Immersion Heaters, Electric Towel Rails, Storage Heaters & Lighting - 13A Timer Switch with Power Monitoring \| Alexa & Google Voice Control \| No Hub Required](https://bargainpostbox.co.uk/visit/timeguard-ntt03-immersion-heater-timeswitch)
- [VAILLANT TIMESWITCH 150 0020116882](https://bargainpostbox.co.uk/visit/timeguard-ntt03-immersion-heater-timeswitch)
- [ANTREATU Immersion Heater Timer Switch 40A Wifi Immersion Heater Switch with an Installation Box, Tempered Glass, Compatible with Alexa & Google Home Smart Switches for Lights](https://bargainpostbox.co.uk/visit/timeguard-ntt03-immersion-heater-timeswitch)
- [Water Timer 3 Outlets with Brass Inlet, Programmable Sprinkler Hose Waterproof Timer, Automatic prinkler Timers with Rain Delay/Manual Watering/large LCD display for Irrigation Lawn Yard](https://bargainpostbox.co.uk/visit/timeguard-ntt03-immersion-heater-timeswitch)
- [Timer Plug Socket Digital Electric Timer Countdown 18 On-Off Programs \| Digital Timer Socket 24 Hours/Weekly Indoor Plug in Electrical Timer for Lights and Home Appliances Switch Timer](https://bargainpostbox.co.uk/visit/timeguard-ntt03-immersion-heater-timeswitch)

## Add-ons

- [Schneider Electric Lisse Dual Surface Pattress, 25 mm](https://bargainpostbox.co.uk/visit/timeguard-ntt03-immersion-heater-timeswitch)

## Images

![Timeguard NTT03 24-hour/7-day immersion heater timeswitch — 1](https://bargainpostbox.co.uk/i/NbAydmABzaNTUPPgIAcoIPEky_t_pDJtnkVXiS8bJEFS20kgBOnKf9Y4_rV_2V9gVPK3sLEnJNNqqElffaTAdcrSNfp5qLUOPPI0rKaO_IarEt2tXEbz-DT6.jpg)