4. How to fix a thermostatic radiator valveOn the other side of the radiator from the water shut off valve, you might have a thermostatic radiator valve (TRV). These work by sensing the temperature of the room, and then regulating the amount of hot water entering the radiator until the room reaches the temperature you've set on the TRV.
One common problem with TRVs is that, after staying closed for months at a time over the summer, they can get stuck into the closed position. Luckily, it's easy to get them going again.
After removing the head of the TRV, you should see a pin underneath where the head was fitted. Using a pair of pliers, start to work that pin up and down until it's moving more freely.
Once you've got it moving, you can use a spray-on lubricant to make sure it doesn't get stuck again. Then you can simply replace the head of the TRV, tighten it up, and set it to the right temperature.