Connectivity Issues: RT500RF, RT300RF. How to change the Address Code?

Issue Description

If you have an RT500RF or RT300RF and you are experiencing problems with communication between the RT500RF/RT300RF and it's receiver, it is highly possible that it might be caused by another device in your area that causes RF cross-talking issue.
Your Thermostat (Transmitter) might try to communicate with another Receiver which operates on the same frequency.

How to solve this problem?

To resolve this problem, you need to adjust the Address Code setting for your RT500RF/RT300RF. If you do not feel confident enough to follow this procedure, you should request Qualified Engineer/Installer to do that for you.

Please follow this simple procedure:

Turn off your boiler, turn off the power supply for your Receiver and remove it from the wall. Remove your Thermostat from the wall. For best visibility place them side by side.
Remove the back covers of both your Thermostat and Receiver. Once you have done that, you will see 5 Jumpers on your Thermostat, and 5 DIP Switches on your Receiver.
Take out two selected jumpers (ex. Number 1 and Number 4) from the RT500RF/RT300RF Thermostats. Then, follow up by switching off the same DIP Switches on your Receiver (Number 1, Number 4). It does not matter which jumpers are taken out, but the same DIP Switches on the Receiver must be switched off for the devices to communicate properly.
Once you have done it, put back-plates back and plug your Receiver's AC Power back, turn your boiler on.
Push the 'RESET' button on your Thermostat to restart the device with new Address Code configuration.