Hi Kieran,
I turned off the power at the mains, i.e. the whole house from the main fuse board.
I would take a photo of the wiring before you replace the actuator, it helped me to know which wire goes where.
The job was a lot easier than it sounds, it's just a little fiddly first time round. Once you've fitted the wires and actuator, then test with the thermostat by turning it up or down to see if the heating comes on/off successfully.
I turned off the power at the mains, i.e. the whole house from the main fuse board.
I would take a photo of the wiring before you replace the actuator, it helped me to know which wire goes where.
The job was a lot easier than it sounds, it's just a little fiddly first time round. Once you've fitted the wires and actuator, then test with the thermostat by turning it up or down to see if the heating comes on/off successfully.