Vaillant VRT350 Programmable Room Thermostat, White

You'll find the setting in the installers menu. If you leave it on 2-point which is the default then you don't get demand compensation. Yet to experience the poor battery life reported by others.

Our thermostat went up it new years eve(not good). On ordering this product on new year's day it said it would be delivered on Friday. It came on the Thursday. All up and running again now. Very happy with the service received. Excellent product.

I had one of these fitted with my new boiler a month or so ago. There are settings that are supposed to control the circulating temperature for the hot water and the heating. But they don't work, these things are set at the boiler and it ignores them. Nothing in the manuals tells you this. The user interface is counter intuitive. It can be set for basic programmes. But if you want to switch on the heating early you need to select "party mode". Party mode turns on both hot water and heating although normal programming allows you to control them separately. You can't just boost the heating, although you can just boost the hot water. If you want an extra hour of heat, the only option is to reprogramme for that day, and of course set the programme back as it was when you've enjoyed that moment. Or turn on Party Mode and waste energy heating water you don't need until the next day. And if you want to turn it off for some reason there is no simple over ride, you have turn it off: "system off". So when you come back after your night out you have to remember to switch it back on or no heating and shower for you in the morning. The installation engineer couldn't figure out how to operate it, he's only installed three (and I think he's cured). When we called technical support they treated us like idiots, but I have studied it and we were not idiots. It really is as I describe.The last straw today and why I am writing this review. I have auto selected "on" for daylight saving. I just noticed that it has jumped forward an hour. In January! The thing is it works reliably, doing what it was designed to do, aside from that daylight saving trick. But the design, as a heating programmer is hopeless. Truly the worst bit of software for such a simple job that I have ever seen. Come the summer, when I can risk disruption I am throwing it away. Do not waste over £100 on this device.

If you fancy spending a constant small fortune on Batteries then go ahead.I have been pulling my hair out trying to get an alternative but to no avail.You have to use the expensive type or it will literally last a few days.You may do well and get 5 weeks out of top of the line "Duracell s".Incredibly frustrating because when they fail,you have your heating full blast come what may and if your away etc which happened to us its infuriating.