On Mar 3, 9:30*am, "Dave Plowman (News)" wrote:
In article
,
You need Part No. 7133 385 according to the installation manual. This
is a wall mounting adaptor plate for the controller and includes a
blanking plate for the front of the boiler.
Maximum cable length is 30M and you need 2 core cable apparently.

*Spoke to Viessmann this morning - what a breath of fresh air getting
straight through to a bloke who obviously knew the things inside out -
when asking for technical advice.

*The part number you gave is correct for earlier units but it seems can't
be done with current ones. What they do supply is a slave unit which looks
the same and duplicates all the operational features of the main one which
stays in place - all it doesn't do is allow access to maintenance and
setup codes/features.

* It does indeed work on only two wires and it's a Vitotronic 300 with a
part number 7248 907 - this is for the weather compensated one.

Good stuff. Is it expensive?

Steve