Most helpful critical review
59 of 65 people found the following review helpful
Great concept, but let down lack of optimisation!
on 22 December 2014
The Nest thermostat has some great features, such as learning your heating schedule and sensing when you're away from home. It also provides a means to turn on the heating remotely from a smart phone, which is a handy feature for people working irregular hours.
I'm a heating engineer and decided to install one in my own home, to evaluate it, prior to making recommendations to my customers ( a few who had seen it and asked me how it worked).
Installation and setup was fairly straight forward, as was the controlling/remote operation from a smart phone. The Nest learns your heating routine during the initial week following installation. During this time, you turn the thermostat up or down at the usual times when you want or don't want heat and you set the temperature you'd like you home to not fall below whilst you're away.
However, after running the Nest for a period of around 4/5 weeks, I found that it was not properly optimised for radiant heat systems (i.e. tradition 'wet' heating systems with radiators), despite the ability to setup this option. I found that the Nest didn't turn the boiler off soon enough and the residual heat in the radiators then continued to heat the room further, resulting in over temperature. The set temperature in my home of 20 degrees C was always overshot to 21.5 degrees. The Nest is also supposed to learn how long it takes to heat up your home to your predetermined temperature and use that calculation for future use and to also adjust this, according to changes in the weather. I found this preheating time rarely very accurate and usually resulted in the heating coming on too early (e.g. 20 degrees required by 5.30 pm - house was up to temperature by 5.10 pm). Both these issues result in actual wastage of energy - a pity, as it sort of defeats the object of installing energy efficient controls in the first place!
Also people should not confuse the Nest's weather adjustments with true weather compensation that works with the boiler to actively reduce or increase flow temperature to the radiators depending on readings from a dedicated outdoor sensor.
I didn't buy from Amazon, but suffice to say the unit was returned to the supplier for a refund.
All in all, a very good concept, but I feel more tweaking to the software is needed to fine tune these so called energy saving features!