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

great bit of kit, very good price and super easy to set up with precise instructions.

Works perfectly, lets me charge my batteries in my garage without having to worry about leaving the power on

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.

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.ProgrammingThe 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.

Can be set for different times on different week days or the same times all week. Changeover from winter to Sumer time can be automatic.

The battery backup is a great feature - absolutely nothing to do after switching the mains power off for 24 hrs to isolate the immersion heater while working on the hot water tank.Switching the power back on, it was a really pleasant surprise to see the correct time of day displayed and it sitting there as if nothing had happened - no need for the setup instructions printout taped up next to it!

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.