This product operates on a frequency of 433mhz, and is not interchangeable with earlier 418mhz units.

If you are replacing an RF component that operates on 418mhz, both transmitter and receiver must be replaced

Frequencies can be identified by the following branding:

418mhz =
433mhz =

British Gas models RC1, RC2, RC5, and WR1 were 433mhz

Worcester Receivers must be 'Issue 2' (printed on the back of the receiver)