1 / 3Timeguard NTT08 7-Day Slimline Electronic Immersion Heater Timeswitch
The Timeguard NTT08 is a slimline electronic timeswitch for programming an immersion heater across a seven-day schedule. It offers four daily on/off periods, a timed boost and battery-backed settings, making it suited to households that want scheduled water heating rather than manual switching.
At a glance
- Set the same schedule every day or programme different switching times across the week, with minute-level switching intervals.
- The listing specifies four on/off periods each day and 28 on/off programmes per week.
- A 1 or 2 hour boost provides extra heating on demand. The override is described as self-cancelling at the next programme change.
- The blue-backlit display and separate mains and output indicator lights show the timer and heater status.
- Rechargeable backup is claimed for up to 720 hours, and the clock changes automatically between summer and winter time.
Reference price: £36.99
Price checked: 14 Nov 2026
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Pros and cons
Pros
- Seven-day scheduling supports different water-heating routines on different days.
- The boost function provides a short, selectable heating period without changing the regular programme.
- Battery-backed memory is useful during power interruptions, while automatic clock change avoids seasonal manual adjustment.
- Slide cover over the programme buttons helps reduce accidental changes.
Technical specifications
21 specifications| Brand | Timeguard |
|---|---|
| Model | NTT08 |
| Supply voltage | 230 Volts |
|---|---|
| Wattage listed | 3680 watts |
| Resistive load rating | 16A |
| Inductive load rating | 4A |
| LED lighting load rating | 100W |
| Daily programme periods | 4 ON/4 OFF easy-set programme periods per day |
| Weekly programme capacity | 28 ON/28 OFF programmes per week |
| Shortest switching time | 1 minute |
| Boost options | 1 and 2 hour boost button |
| Battery backup | 720 hours rechargeable memory back-up |
| Clock adjustment | Automatic Summer/Winter changeover |
| Dimensions | 121 x 74 x 42mm |
|---|---|
| Mounting | slimline surface mount design |
| Cable entry | Back and bottom cable entry |
| Weight listed | 0.19 Kilograms |
| Material listed | Plastic |
|---|---|
| Construction | Class I construction |
| Ingress protection | IP20 rated for indoor use |
| Product warranty | 3 years. |
|---|
What to know before buying
Listing details to confirm
Listing specifications are not fully consistent: one feature describes 4 ON/OFF periods per day, while the product description says 4 ON/4 OFF per day and 28 ON/28 OFF per week. It also lists 3680 watts, a 16A resistive rating and 100W LED rating without explaining how the figures relate. Confirm suitability with a qualified electrician. Installation by a qualified electrician is recommended. The listing says Class I construction and states that the unit must be earthed. It is IP20 rated for indoor use.
What’s in the box
Included- 1 × Slimline Electronic Immersion Heater Timeswitch
Who is it for?
A good fit for
- Households wanting an immersion heater schedule that can vary by day of the week.
- Buyers who value a timed boost and visible status indicators on a hardwired timer.
Less suited to
- Those who need remote or app-based control, which is not listed as a feature.
- Buyers wanting a plug-in timer rather than a surface-mounted installation.
Customer reviews on Amazon
- 5 stars
63% 63% - 4 stars
26% 26% - 3 stars
7% 7% - 2 stars
1% 1% - 1 star
3% 3%
Customer feedback describes the timer as easy to set up and programme, with a clear display and useful controls. That aligns with its stated seven-day scheduling, backlit screen and boost button, which may matter to buyers who adjust water-heating times regularly. The supplied feedback does not establish how it performs in every installation, so confirm electrical suitability separately.
Positive themes
- Customers report that setup and programming are straightforward.
- Customers describe the display as clear and appreciate the controls and boost function.
Frequently asked questions
Can the NTT08 use a different schedule on each day?
The listing says it can be programmed with the same times every day or with a full seven-day schedule.
What does the boost button do?
It provides a selectable 1 or 2 hour boost. The listing says the self-cancelling override ends at the next programme change.
Does it retain settings during a power cut?
The listing claims rechargeable memory backup for up to 720 hours, equivalent to 28 days.
Does installation require an electrician?
Professional installation by a qualified electrician is recommended. The listing identifies it as Class I construction and says it must be earthed.
Alternative options
Timeguard FST24 24 Hour Digital Fused Spur Timer with Boost, 13A 3kW, Battery Backup, White
£26.13
Timeguard NTT03 24-Hour/7-Day Compact Electronic Immersion Heater Timeswitch,White
£31.15
Timeguard TS900N 24 Hour Immersion Heater Time Controller, 13A 3kW, Mechanical Plug-In Timer, 24 ON/OFF Settings Per Day, Self-Cancelling Manual Override, 3 Year Guarantee, White
£15.29
LOWENERGIE 24hr Mechanical Wall Timer Switch – 16A Hardwired Control for Immersion Heaters, Lighting, Fans & Energy Storage Systems (3000W Max Load)
£14.99
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
£39.99
HBN 24 Hour Indoor Energy Saving Mechanical Immersion Heater Segment Timer Switch with Waterproof Cover, White, 16 Amps
£15.99
