Installation Instructions; Safety Instructions - Viessmann HMU Notice De Montage

Installation instructions

for contractors
Replacing the HMU electronics module

Safety instructions

Please follow these safety instructions closely to prevent accidents
and material losses.
Safety instructions explained
Note
Details identified by the word "Note"
contain additional information.
Installation, initial start-up, inspection,
maintenance and repairs must only be
carried out by a competent person
(heating engineer/installation contrac-
tor).
Before working on the equipment/heat-
ing system, isolate the power supply
(e.g. by removing a separate mains
fuse or by means of a mains isolator)
and safeguard against unauthorised
reconnection.
VIESMANN
When using gas as fuel, also close the
main gas shut-off valve and safeguard
against unauthorised reopening.
Repairing components which fulfil a
safety function can compromise the
safe operation of your heating system.
For replacements, use only original
spare parts supplied or approved by
Viessmann.
GB
7