Better heating control can help reduce wasted energy and improve comfort. Appropriate upgrades may also support improvements to your home’s EPC assessment, depending on your existing system and the changes made.
This guide explains how smart thermostats and TRVs work, what they may save and why compatibility matters.
For a wider view of controls, radiator performance and choosing an upgrade, explore our heating controls and zoning advice and whole-system heating efficiency approach.
You may already have an A-rated boiler. But does your heating schedule still match your routine? Are some rooms warmer than you need? And are your controls straightforward enough that you actually use them?
These are questions worth asking before assuming that better heating means a replacement boiler.
At SwiftHeat UK, our approach is simple: Assess First. Recommend Second. We look at your home, your existing heating system and your household’s needs before recommending what should change—or whether anything needs replacing at all.
An efficient boiler is only part of the picture
A boiler’s appliance energy rating describes its rated performance. It is not a measurement of how effectively your household manages its heating or how efficiently the complete installation operates in your home. [7]
Condensing boilers recover heat from exhaust gases that would otherwise be lost. Suitable heating-water temperatures and compatible controls help the system make effective use of that capability. [7] [1]
The distinction matters: producing heat efficiently and avoiding unnecessary heating are two different objectives. A well-assessed system should address both.
What does a smart thermostat do?
A smart thermostat combines temperature control with connected features, usually including an app. Depending on the product, it may also offer learning functions or location-based settings that help your heating respond to your routine.
For example, when your plans change and you will be home later than expected, remote access lets you adjust the heating instead of leaving it to follow an unsuitable schedule. Some systems can also respond automatically when you leave home. Features vary, so the specific product matters. [1] [3]
The useful question is not simply, “Does it have an app?” It is, “Will this make it easier to manage my heating?”
What do thermostatic radiator valves do?
Thermostatic radiator valves—TRVs—help regulate temperatures in individual rooms.
They sense the air temperature around the valve and adjust the flow of hot water through the radiator. As the room approaches the selected temperature, the valve reduces the flow; when the room cools, it can allow more water through.
This helps you maintain different temperatures in different rooms—for example, a warmer living room and a cooler spare bedroom. Conventional TRVs usually have numbered dials, but the corresponding temperatures vary between models. [1] [3]
How are smart radiator valves different?
Smart radiator valves add functions such as app control and individual room schedules. With compatible equipment and the correct settings, they may also request heat when a room needs warming.
For example, Hive radiator valves can request heat through compatible Hive heating controls when Heat On Demand is enabled. Without the necessary integration and setting, they regulate their radiators only while the heating system is already supplying heat. [8] [9]
However, requesting heat for one room does not necessarily mean only that room will warm up. Other radiators with open valves on the same active heating circuit may warm up too. Effective room-by-room control therefore depends on the wider installation, not just one smart valve. [9]
How much could better heating controls save?
Your starting point matters. Energy Saving Trust publishes two useful examples for Great Britain:
Around £100 a year: installing and using a full set of controls—a programmer, room thermostat and TRVs—in a home without them. Energy Saving Trust describes this example in the context of an average semi-detached house. [2]
Around £30 a year: adding TRVs to a heating system that already has a programmer and room thermostat. [3]
These figures describe different improvements from different starting arrangements. They should not be added together or presented as guaranteed savings from installing a smart thermostat. Actual results depend on the property, existing controls, heating habits and energy prices; published estimates are not personalised forecasts. [6]
Smart controls can also increase energy use when their convenience leads to longer heating periods or higher temperatures. Better control creates an opportunity to reduce waste—not an automatic reduction in your bill. [4]
Can smart thermostats and TRVs improve your EPC?
Appropriate heating-control improvements can contribute positively to an Energy Performance Certificate, or EPC. Energy Saving Trust includes heating controls among the measures homeowners can consider when improving their property’s energy performance. [2] [5]
However, installing a smart thermostat or TRVs does not guarantee a higher EPC score or a move into a better band.
An EPC assesses the property and its energy-related features, rather than simply the technology or brand of an individual device. The benefit of an upgrade depends on the existing installation and how the completed arrangement is recognised in the assessment. A boiler’s A rating and a home’s EPC rating are different things. [5]
Start with the recommendations on your current EPC. When reaching a particular band is the objective, discuss the proposed work with an accredited domestic energy assessor before purchasing equipment solely for that purpose.
Compatibility matters more than the word “smart”
Remote access is useful, but it is not the only control feature worth considering.
With compatible equipment, load compensation adjusts the temperature of the water supplied to the radiators as the home approaches its target temperature. Weather compensation adjusts that temperature in response to outdoor conditions. These functions help match heat delivery to demand; app connectivity alone does not establish whether a system supports them. [1] [10]
Positioning matters too. Hive, for example, advises against fitting its radiator valves in the same room as the main thermostat because conflicting temperature settings can cause control problems. Installation should follow the guidance for the specific equipment—not assume every system works identically. [9]
Start with comfort—and the controls you already have
Before buying new equipment, identify what you would like to improve: room temperatures, heating schedules, ease of use or compatibility. That gives an assessment a clear purpose and helps distinguish a useful upgrade from an unnecessary purchase.
The objective should remain a comfortable home. Energy Saving Trust advises prioritising comfort and health over energy savings, and avoiding leaving rooms completely unheated for long periods during colder weather. [1]
Get more from the heating system you already have
At SwiftHeat UK, we assess your existing system and explain the options in relation to your home and heating requirements.
That may mean adjusting the controls you already have, recommending a compatible upgrade or identifying a wider issue that needs attention.
We do not begin with the assumption that every home needs the same product—or a new boiler.
Already have an A-rated boiler? Let’s find out whether your heating controls are helping you get the most from it.
For advice on smart thermostats, TRVs and heating controls in Cardiff and across South Wales, call or WhatsApp SwiftHeat UK on 0800 043 3464.
Assess First. Recommend Second.
Keeping Homes Warm Across Wales & the UK.
Sources and further reading
- Energy Saving Trust — Heating controls
- Energy Saving Trust — How to improve your EPC rating
- Energy Saving Trust — The most economical ways to use your central heating
- Energy Saving Trust — Smart homes and energy use
- Energy Saving Trust — EPCs explained
- Energy Saving Trust — Energy-saving data and assumptions
- Energy Saving Trust — Boilers explained
- Hive — Using your Hive Radiator Valve
- Hive — Radiator valves explained
- Worcester Bosch — Boiler controls explained
- Worcester Bosch — Boilers explained
Sources checked: 2 October 2026.