Optimum OP-BM/IHTWF01 Wi-Fi Enabled Universal Boiler Module/Immersion Heater Control, 230 V, White

Bought this for our oil boiler as the old timer broke off. Took a little bit of time and number of tries but got it working with professional electrician.My original wires were brown (live) and blue (neutral) for main power and one blue (neutral) and 2x brown (live) from the boiler.There is 5 different position and one earth on this module. I wired it as follows.Position 1 - Both neutral wires (one from mains and one from boiler)Position 2 - Live wire (blue) from mains.Position 3 - First live (brown) from boilerPosition 4 - Second live (brown ) from boilerPosition 5 - not in useEarth - not in use as i have it connected to earth from before.Hope this setup works for you as well.Once it was connected, it could be switched on and off with the button on the module. The Wifi setup was really easy using the app as per manual in the box. So far we have had no issues and all is working well.There is number of different timers you can set up in the app as well as remote control the on and off button.Very pleased with the purchase.

Arrived promptly and relatively easy to install, provided you understand how to safely fit mains electrics and know which wire is which. Note the switch is not compatible with a standard socket box width and the screw holes don't match up so if you're replacing one that's currently using one, you'll need to remove that and make new holes. Luckily it's narrower and fits flush against a surface, but do check the dimensions given in the description before buying.The 'C-Home' app to control the timer is 'Chome' on Android as there appears to already be another 'C-Home' app which is not the app you want. This makes it tricky to find on Google Play which assumes you might have mis-typed Chrome, but it does appear in the list just further down.The app's a bit quirky too and includes a Programmer function for time related controls (on/off, days of the weeks etc.) that you'd expect. The countdown allows you to flick switch after a specific time interval. Its a bit confusing, but if you want to the device switch to be on for a period of time (eg for a boost, say) you have to switch the device on before you set the countdown timer - a bit more fiddly than the usual 'boost' function you have would on a traditional controller, but workable once you've sussed it.There's a random function in the app too - presumably intended for controlling lighting rather than a water heater.Probably the most frustrating thing has been that the app looks as tough it should link to Google Home / Assistant, but just seems to hang when you try to connect. Google Home does not include the C-home in the apps that come up under its Works with Google setting. In the end, I used the Chome app to connect and name the device and programme in the timer function, then uninstalled the app and connected it manually in a smart switching app I had for another device which then allowed it to be added to Google Home.Once added to Google Home you can then use the app or smart speaker to switch it on or off outside the programmed timer settings. I thought I'd then be able to ask the Google Assistant to switch it on for 1 hour (to replicate the boost function), but apparently Google don't allow that on switching devices for safety reasons. Not sure why a boost while you are likely to be in the house is less safe than allowing a programmed timer operate the switch (possibly unattended), but someone somewhere in Google towers has obviously decided to programme that option out.So on balance, relatively easy to physically install if you know what you're doing electrically, certainly appears robustly made physically, does connect to its' own app (once you have the right one installed) but, the app is not so clever functionally, and was even trickier to incorporate into Google Home.Once you've got round those issues, though, it appears to work well as a programmable timer, overrides programming via a button on the unit and also over wi-fi by app and does most of what you'd need from an immersion heater switch. A single step boost option would have been useful.

This device is great for both convenience and saving money. I am on an Octopus Agile tariff which means the prices for energy change half hourly based on wholesale prices. Using Home Assistant I am able to run the timer at the cheapest 4 hour block to heat my water (typically overnight) or use as an energy drain when we are paid to use energy.I've experienced good connectivity through a wall in an airing cupboard and setup is simple. The backend is backed by Tuya and had no luck flashing Tasmota or ESP home unfortunately, which means I can't control this device without a working internet connection (as it has to talk to the cloud).Wiring was relatively simple although you need to strip back a lot of wire as the poles are far away from eachother and common is a bit of a stretch. You can also take out the bus bar and effectively isolate the switched side of the device if you want, if you leave it in it will jump it from the mains.I noticed the device get slightly warm under a 3Kw load.UPDATE:Unfortunately after ~3 months the unit has failed. It looks like the internal relay/smart controller component has melted. Very unfortunate...