Yes – solar thermal can be used for central heating. Solar thermal panels work by collecting heat from the sun, either through evacuated tubes or flat plate collectors, and transferring that to a heat transfer liquid that heats your hot water. This can then be used to preheat your central heating.
You’ll need a hot water cylinder to store the water that your solar thermal panels heat up. It’s likely that you’ll need an immersion heater or boiler to heat the water further so you can use it for your central heating, and as a back-up during the longest winter months since the solar panels won’t be able to generate as much heat.
In our opinion, it’s best to use your solar thermal panels for hot water rather than your central heating. That’s because you use hot water all year round, whereas you probably won’t have your central heating on in the spring and summer, when the panels can generate the most heat. For central heating, air- or ground-source heat pumps are a great renewable option, and you can even power them with electricity from solar PV panels if you want to be as eco-friendly as possible.