The biggest buzzword in the heating industry at the moment is ‘control’. Simply put, more control means better tailoring of your space heating and hot water setup, which should ultimately get you closer to the holy grail of only using exactly as much energy as you actually need to create a comfortable living environment.
“There are many homes in the UK without even basic heating controls,” explains Nigel Griffiths, Build It’s sustainability expert. “Putting in a standard programmable timer gets you 75% of the way there in terms of the potential savings. The other 25% is about getting clever with zoning, temperature control in rooms and suchlike.” And that’s where the latest whizz-bang thermostats come in.
What is smart heating?
Fundamentally, this tech allows you to control your home’s central heating system from your tablet or smartphone, wherever you are in the world. While that may sound a little gimmicky, there’s a practical point to it.
Gone are the days where, to get maximum value for money out of your heating, you’d have to literally run around the entire house adjusting each thermostatic radiator valve and refining the overall temperature – now you can do everything with the push of a button.
“If you want the room at 15°C, you just type that in and the room sensor will stop calling for heat when that temperature is reached,” says David Hilton, an independent sustainability advisor who delivers eco courses at the National Self Build & Renovation Centre. The ability to fine-tune each room or zone’s heating means you can easily achieve exactly the right climate throughout your home, and potentially save money in doing so.
Smart TRVs, such as this Netatmo design, allow you to get unrivalled control over the heating cycle for every room in the house
How does smart heating work?
The tech basically involves swapping your existing thermostat with a smart version that gives you a digital control panel and app access. This allows you to see and set what your heating system (and usually your hot water, too) is doing at any given time, whether you’re at home or away.
Systems such as Worcester’s Wave can manage a single zone, with the thermostat usually placed in a central location such as a hallway. They call for the boiler to provide enough warmth to reach the desired temperature in their vicinity, and therefore rely on thermostatic radiator valves (TRVs) to manage conditions in individual rooms.
Setups such as Heat Genius go a step further, allowing discrete control of every room via smart thermostatic radiator valves (STRVs). These are a straight swap for conventional TRVs, and are linked back to the app via a special hub and boiler controller.
The big advantage here is that you can literally programme timings into individual radiators – so the bathroom heating could come on for an hour in the morning, for example, completely independently of other rooms in the house. A number of other providers, including the likes of Netatmo and Tado, now offer room-level control via STRVs as well as multi-zone setups.
Is it really better than using standard controls?
Think of it this way: you may already have a programmable timer and perhaps even a couple of heating zones in your home. But how much control do you really have over when your boiler or renewable appliance is warming each room in the house?
Unless you’re constantly in the property and willing to actively change your heat emitters’ settings several times during the day, the answer is probably not as much as you think. A central heating loop that covers the whole ground floor could, for instance, be supplying a living room in the morning that simply doesn’t get used because the family takes breakfast in the kitchen-diner.
And what happens if you’re out of the house unexpectedly? “Let’s say you decide to meet up with a friend after work, rather than heading home as you normally would,” says Nigel Griffiths. “With a smart setup, rather than having the heating on for several hours unnecessarily, it simply takes a couple of swipes of your phone’s touchscreen to switch it off and set it to come back on for an hour or so before you go to bed.”
Moss Technical's Niko home control works across a range of smart systems. The main touchscreen gives you instant graphical feedback on usage statistics
“For many of us, knowing when and how to set our heating controls for best effect can be a mystery,” says Martyn Bridges, director of technical support at Worcester.
The intuitive design of app-based management tools helps; but one of the biggest leaps forward in smart thermostat technology has been the addition of learning functionality. “The latest version of the Wave app takes the guesswork away by monitoring your usage and automatically setting the system up to meet your heating and hot water needs in the most fuel-efficient way,” says Martyn.
In addition to responding to your usage patterns, many of the latest smart thermostats include weather compensating features to ensure optimum performance. They can also learn how long it takes to heat your home to the desired temperature.
Some actively sense when the house is empty, often by using a combination of motion sensors and GPS tracking. This enables them to automatically switch to an ‘away’ mode to conserve energy; or to warm the house up when you’re nearly home. The newest STRVs are even able to detect when a window is open in a room and shut down to avoid wasting energy.
How easy is it to install?
Many smart heating systems are relatively straightforward for a competent DIYer to install. The trickiest bit is usually hooking up the new boiler control box. But most providers offer a cost-effective supply and fix service that tends to be worth the extra outlay for peace of mind. If you go down this route, take the chance to get them to demonstrate how everything works and, ideally, put a basic programme in place.
You can install smart tech on pretty much any central heating system – including many renewable appliances – but it’s worth double-checking with the manufacturer before you buy. Some smart tech firms offer handy online compatibility checkers.
The installation costs will vary significantly depending on the level of interaction you want and how many zones/rooms you want to manage this way. Worcester’s single-zone Wave learning thermostat costs around £250 when installed by a qualified heating engineer, for instance. But you could easily spend much more.
If you want multi-zone control with a product such as Hive, you’ll need to buy the starter kit for £249 (comprising a hub, boiler control and thermostat) plus another thermostat for each zone (at £99 a pop).
For a top-end system that includes all the main kit along with smart TRVs (typically £50 each) and sensors for every room in the house, you might be looking at £1,300 plus. Clearly, that’s a big investment, but the extra controllability is likely to net you lower running costs – and if your home doesn’t have multiple heating zones, this could be the simplest route to creating them.
The Loxone miniserver gives you the ability to centrally manage everything from heating through to security, audio, blinds, solar panels and more
How much can I save?
The truth is it’s difficult to say, as every project is different. Many suppliers suggest you can significantly cut usage. For example, Tado’s website states its system can deliver savings of up to 31%, while Netatmo reckons its smart tech can reduce energy usage by 37%.
Those are pretty bold numbers, but some homeowners have achieved them – with their setups paying for themselves in just a few years. But if you’re already fairly energy conscious, you’ll see smaller gains and a longer payback period.
“While you can absolutely save money, personally I wouldn’t put my name to a percentage because it all depends on the occupants’ lifestyle,” says David. “If you’re used to running around the house all day, every day adjusting the radiator valves to give you optimum performance, you won’t get a big saving – but what you will find is that, now it’s all automated, your life is a lot easier.”
On the other hand, if you haven’t been engaging fully with your central heating, you can be confident your bills will drop significantly. “Compared to just leaving the TRVs wide open, you’ll suddenly be able to easily set your rooms up with specific target temperatures, and that will translate into instant savings,” says David.
Image (top): Worcester's Wave thermostat and app learns your usage patters to help optimise the load on your boiler
First published: December 2016