Thank you for the replies.

To answer the questions:

1. The Xantech is a 12 V receiver
2. I have got the IR mode set to controller
3. It is the only Meridian device so my only option is IR to it

Since my first post my dealer tried the receiver with a 251 and it worked perfectly but did not work with 2 other 218's

Thechnote TN094 states that a 218 must have firmware with a build greater than 185.

Mine is 185. Could that be the issue?

If so how can it be updated?

861v8+ID41 Revelation One filter, HD621, Musical Fidelity M8 700 mono blocks, Focal Scala (x2), Focal Mini Utopia (x3), Velodyne DD18, Oppo BD105, Roon NUC, 218, Radiance 2021, JVC X9000