Timeguard NTT03 24-Hour/7-Day Compact Electronic Immersion Heater Timeswitch,White

I decided to fit this to my immersion heater as the cost of oil has increased, and using electricity on a timed schedule is now working out much cheaper. The unit arrived well packaged and feels solid and well made. Once installed, the display is clear and easy to read, and the indicator lights make it obvious when the unit is powered and when it’s actively supplying the heater. Installation is fairly straightforward if you’re comfortable with wiring. The terminals are a decent size, so handling the heavier-duty cables typically used for immersion heaters isn’t a problem. Programming is also quite simple once you follow the instructions properly, and having multiple on/off periods is very useful for taking advantage of off-peak electricity. My only real caveat is the depth of the unit. It’s not particularly slim, and with heavier cables in the back box space can be tight. In my case, I fitted a 10mm spacer between the wall and the unit, which made installation much easier and avoided having to force the wiring into a confined space. I’ve included a photo of this so you can see how it sits. I’ve also included a photo of the unit installed, which gives a good idea of the finished look. Overall, this is a reliable and easy-to-use timer that does exactly what it should — just plan ahead for the depth when installing.

This 24 hour / 7 day immersion heater time switch replaced an old 24-hour electro-mechanical time switch. It was easy to install; the connections are very robust and offer ample opportunity to get a good grip on the cables! When I switched the immersion heater circuit back on at the consumer unit, the first thing I noticed was how much less electricity it used, compared to the old electro-mechanical switch. Whilst you could never say that the old switch guzzled electricity, there was a slight but noticeable slow down in the wheel in my meter. However, when I switched the electricity back on after installing this, there was no noticeable speed up of the wheel in the meter. This brings me to why we replaced it; more than half of the week, we don't need the immersion heater on; so for those days, our water was heated up and went cool without being used. Now we can set four on and off times for each day - so we only need to heat the water on the days we need it! For us, with definite usage requirements, this was a great advantage, and one that will save us lots on our electricity bills; your mileage may vary. The unit itself is easy to programme, it has a very bright blue display, and is very versatile. Despite what others have said, it is possible to switch it permanently on, and permanently off. It's a nice compact unit, is easy on the eyes and on the wallet!

I purchased this unit to replace a standard wall switch. As our oil fired water heater died, we are entirely reliant on the immersion heater for hot water at the moment. However as it was fitted with an ordinary on/off switch there would be little or no hot water first thing in the morning and it was far too easy to forget to turn it off, which soon starts costing a fortune. The water heater is now programmed to come on for a half hour before anyone gets up (and while the power is cheaper) and to turn off at several times throughout the day (in case it somehow gets turned on and forgotten). We can also get a 1 or 2 hour 'boost' on demand and not worry about forgetting to turn it off. The NTT03 fits into a standard pattress box, but it might be a bit of a squeeze if you have a lot of excess wire. There is no Earth connector on this switch, so you might want to have some wire nuts on hand in order to securely connect the earth wires together if there is no earth terminal in the pattress box. Wiring took ~15-20 minutes, including removing the old switch. The terminals are clearly labeled and the instructions straightforward. The only caveat is that the screws holding the bezel in place have _very_ shallow phillips heads (none of my crosspoints could actually get any grip on them). I had to resort to a small flathead screwdriver to get them in and out or risk stripping the head. The instructions for setting up the timer are straightforward (pretty much identical to every other unit of this sort that I have ever used) As an added bonus, The display is backlit while in use so it's easy to see what you are doing. Unit has a built in rechargeable battery so it should keep settings for a good while if it loses mains power or gets turned off at the breaker/isolator. Straight forward installation, Straightforward operation. Does what it's supposed to. I docked a star for the needlessly cheap bezel screws which could have easily been stripped making the whole process a lot more difficult. Note. that this unit NTT03 is set up 'out of the box' for an immersion heater, the included instructions suggested that the NTT04 'general purpose' switch would also be suitable but might need additional adjustments during installation.

I have a heated towel rail which is run on central heating when on but in summer uses an electrical element. To date I've been switching on and off manually, when I remember! I bought this unit to take out the manual element and it is fantastic. It is easy to programme and instructions were very clear, works the same as most electronic programmers, taking only a few minutes to set up. It does protrude quite a bit from the wall box but that's not an issue for me where it is located. When I wired it up I had to add an electrical joint for the earth wires as there is none fitted to this unit, which wasn't a problem but did make it a bit tight to fit in a standard wall box. Don't really know why there isn't an earth point fitted to the terminal block as standard which would have saved me rummaging around for a suitable terminal block myself, but not an issue really. Had it all wired in and operational in about 45 minutes and am delighted with the silent operation. The display light goes off after a few seconds of not pressing buttons and the red power light stays on all the time but is not obtrusive. The green light comes on to indicate when power is being supplied to the towel rail. Overall a nice piece of kit that does just what it says on the package. Highly recommended and will be fitting another when I revamp my main bathroom in due course.

This timer is great! Fitted it to control the heater element in my 23 year daughter hot water tank. The reason for fitting was she kept leaving the heater on for hours and forgetting to tun it off. You can imagine the electricity bills which were high for someone living on their own. Fitted the timer and set it to come on for an hour in the morning and the same just before she came home in the evening this has now reduced the electricity bill by over 50% in the first month. The other advantage is this timer has a boost button were you can switch the heater on at any time just to quickly heat up the water and it will then automatically switch off after an 1 hour or you could set it for 2 hours if needed, so it does not matter if you forget.. Instructions that came with the heater the print is very small and difficult to read. I when onto the internet found the instructions the the Timeguard web site which made things a lot easier. The only extra purchase which was needed to install this timer was a deep switch box as the standard switch box is to shallow to allow room for the wiring and connections. Very easy to install and set timer and is now proving its worth in savings.

Ordered this "Timeguard NTT03 24-Hour/7-Day" programmable timer for my immersion heater so that I dont have to keep getting up early to turn the immersion heater on manually. Works perfectly exactly as described. Easy to install & program. I live on a narrowboat & sometimes I dont have mains electricity, so I turn off the immersion heater electric circuit when I'm out boating, & this still keeps the correct time, & programmed settings. Still working perfectly after 7 years & 6 months, & it has only gained 30 minutes on the clock after all that time. It was showing 2pm when in actual fact the real time of day was 1.27pm, after 7 1/2 years of continuous operation.

Excellent Product! Had the misfortune to lose my hot water on new years day (we only have hot water from an immersion tank) after some investigation I identified the fault as the old timer switch, it was new years day and my local B&Q was open so I bought one of their own branded switches, it lasted 6 days before it too packed up. So I spent last Sunday (8th Jan) on line looking for a quality switch that wasn't too cheap or too expensive. Came across this item on Amazon and it had excellent and consistent positive reviews so I ordered one. I installed it yesterday (14th Jan) and after a bit of a battle to get it out of the plastic seal it came in I was ready to go. The manufacturers recommend a 32mm back box but I used a 44mm back box, the idea being that there would be more room in the back to allow for the earth leads on my cabling to be tucked in there connected together with a terminal / cable connector, but as it happens I didn't need to connect them as the back box had a earth terminal built in so I just made the earths longer by stripping back a bit more of the outer cover. The switch was really easy to connect, it provides 4 terminals (2 x live (one for the switched live) and 2 x neutral) the holes for the wires on the terminals are nice and large to allow for the thicker cable used on immersion heaters. Once it was all wired up I screwed it into the back box (it comes with the screws) then put the timer in place and reattached the bezel. The instructions do recommend that the switch is left for at least 15 minutes after powering on to let it charge up but they do also say that if the display is blank it should be allowed 4 hours before it is programmed. Programming The instructions specifically say that the reset button should be pressed BEFORE you program it. I'd read this but in my eagerness to set it up after waiting patiently for hours I steamed straight in and set up the date/time then scratched my head thinking I had yet another dud switch as the minutes on the clock then ticked up as if they were seconds. Then the lightbulb went on in my head and I remembered I had to reset it first. After resetting it I followed the instructions (which are very clear and easy to follow) and set up the date and time then the programs i needed to suit our needs for hot water. The display is nice and easy to read and it lights up blue when you are adjusting the time/date or programs making it easier to read in a low light which, if it's in an airing cupboard (like mine) is a good feature to have but please not that the blue back light is not permanently on. The power indicators on the switch are very good too, confirming that it has a supply and that is is supplying the immersion heater when the programs are in use. It does stick out from the wall a bit more than our old switch but it in no way intrudes into the storage space. I know I've only just installed it but I am very impressed with the installation and set up as well as the quality and features and it has worked flawlessly since I set it up. OK there may be better out there for 2 or 3 times the price but I think this is a little gem of a switch for a good price. Can't recommend it enough.

Really easy to install and works a treat. Boost function works really well and the ADVANCE and OVERRIDE functions are easy to understand. I’m using this for my central heating and it’s a much more cost effective timer than a central heating programmer (which I know can be thermostatically controlled but costs £100+) Other reviewers mentioned boost function not turning their heat on but works fine for me. Setting times can be a bit laborious and I cannot find a way of deleting a programme (e.g. if I no longer want 7-8pm I cannot switch a programme off, yet changing it to 00:00 - 00:00 switches the oil on but not off which lead to a very toasty Christmas night!) Anyway all in all, a great timer.