User Guide
Viega Hydronic Mixing Block
1 of 20
UG-HC 566234 0720 Hydronic Mixing Block
Viega products are designed to be
installed by licensed and trained
plumbing, mechanical, and electrical
professionals who are familiar with Viega
products and their installation.
Installation by non-professionals may
void Viega LLC’s warranty.
This document is subject to updates.
For the most current Viega technical
literature please visit
The Hydronic Mixing Block is a mixing device
and boiler control with a built in circulator and
system controller. The block can provide either
a fixed or reset water temperature via start/
stop or constant fluid circulation. The following
pages outline step-by-step instructions for the
installation, piping/wiring, and programming of
the Hydronic Mixing Block.
CAUTION!
Only suitably qualified individuals with
formal training in electrical and HVAC
controls should attempt the installation of this
equipment. Incorrect wiring and installation
will affect the warranty provided with this unit.
Wiring must be completed in accordance with
the codes and practices applicable to the
jurisdiction for the actual installation.
CAUTION!
The Hydronic Mixing Block is a
microprocessor based controller and
as such is not to be regarded as a safety
(limit) control. Please consult and install the
heating or cooling appliance in accordance
with the manufacturer’s recommendations.
Wiring Terminal Block
Delivery Fitting (3)
¾" Solder
Connection*
Return Fitting (2)
Fitting Clip
Supply Fitting (1)
Backplate
Display Screen
Adjustment Buttons
Pressure/Temperature Sensor
¾" Solder
Connection*
Part No 56160
*Viega tailpieces may be used in place of solder connections.
Viega tailpieces are available for sale separately. See “Viega
Tailpieces for Use with Hydronic Mixing Block” on page 3
for options.
