To re-pair the RT520RF or RT520TX thermostat then please follow the steps below

- Ensure the receiver is set to Auto and On

- Turn off the boiler at the mains switch on the wall for 10 seconds

- Turn the boiler back on - The lights should briefly flash then settle on a solid red light

- Quickly flick the receiver switch Off and On, to get the red flashing light

- On the thermostat  press the Settings (Cog) button - It will say SCHEDULE –  

- Using the Arrow buttons , scroll until PAIRING is displayed,  and press tick.

- It  will say TEST - Press DOWN - It will say PAIR - Press OK - It will then say 'PAIRING 10'

- Ensure the thermostat is at least a metre away from the receiver and after a few moments  the red flashing light should turn solid

- Press the Settings button to return to the main screen and the devices should now be paired - You can test by turning the temperature Up and Down.

RT520RF - Pairing with the RXRT520 Receiver