I have been doing a little research on this.
I have a Worcester Bosch boiler and it seems there are various generations of heating control systems. The cheap and cheerful mechanical timer gave way to a thermostat connected by wire or radio to one room, usually in the hallway. That involves just changing out the mechanical timer module with a remote module. Later versions of remote modules handle various kinds of schedules, the idea is you configure it so the heating comes on to suit your pattern of use…it rather presumes you know what that is and it is regular. There are also third party modules from companies like Solus.
However, these things are not particularly smart, they are fixed to monitoring the temperature in one room. There is no app, no web page and no control over individual radiators to set the temperature in different rooms.
They do have a range of smart controls that do this, Easycontrol. They are very snazzy. However, there is a big catch. Don’t expect it to work your boiler if it is more than a couple of years old. Mine is 10 years old and I can’t justify the expense of swapping it out.
There are third party controllers and I looked at Tado. It looks nice, but there is a catch there as a well. It is one of those ‘Cloud’ services. You have to register with their website, agree to pay a monthly service charge and then you get access to a web page that tells you how much energy you use and allows you to configure it to your needs. They also have an ‘app’ for your smartphone that allows you to control your heating system remotely. This is very smart, it will detect when you leave the home and switch off the heating accordingly. If there are other members of your house hold, it can also monitor their movements through their smartphone.
Very convenient, but I feel very uncomfortable about being monitored in this way and I don’t much care to add another direct debit to my monthly outgoings.
Moreover, I notice that these systems do not integrate with the boiler controls in a very sophisticated manner. They simply switch the boiler on and off and allow you to set the temperature of the radiator thermostats. The Worcester Bosch Easycontrol system is rather clever than that, it can moderate the water flow from the boiler through the radiators to achieve a target temperature. Third party solutions just switch the boiler on and off so the rads get hot, it switches off, the rads cool down, then the boiler switches on again. On off, on off, on off. The radiator thermostats also have a gotcha. They thermometer is built into the mechanism and so is exposed to the heat of the radiator and any curtains of obstructions to airflow will make them think it is hotter than it actually is in the room. For a radiator to set the right temperature, it needs to be monitoring the room temperature on wall somewhere with good air circulation.
There are third party systems that do integrate closely with boiler controls and there is an open standard for new boilers like Opentherm. But if you already have a boiler it seems to be a case of opting for one of these simple boiler on-off systems with an ‘app’ and and integration with Alexa or some other voice activated gadget. These seem all smoke and mirrors.
I am now looking at the Drayton-Wiser system,which has an on off controller and remote controlled radiator valves, but without the big brother aspect of the Tado system. I am experimenting with the Homeassistant home automation system and have cheap temperature sensors in all my rooms. So maybe I can do something with that, at least switch of the rads I don’t need to be on.
Quite frankly I very unimpressed by boiler and heating controls and the state of the market. Fine if you are installing a new boiler, with the latest controls and can afford the several thousand pounds that will involve. But that investment has to be considered in the light of the governments intention to phase out gas boiler installations in the next few years.
I appreciate that if you have large home and you have big bills to contend with right now, then one of these solutions may work for you.