Viega Hydronic Mixing Block, User Manual, Page: 15 / 20

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Viega Hydronic Mixing Block User Guide
UG-HC 566234 0720 Hydronic Mixing Block
Status Screen
The STATUS screen shows the actual
temperatures as read by the sensors and the
target temperatures the control is trying to obtain.
■ HEATING — If the display screen is red and
heating is displayed on the upper left corner
of the STATUS screen, the control is in heating
mode and there is a boiler demand. If the display
screen is blue, it means there is a heating
demand but the boiler is off. If the screen is light
blue/gray, there is no heating demand.
■ BOIL SUP/RET — The temperature of the
boiler supply/return. This will be dictated by the
sensor location. If on the supply this will read:
BOIL SUP. If on the return it will read BOIL RET.
When the boiler sensor is bad or there is a
broken/ shorted wire, it will be represented by 5
dashes ----- in the supply field and the display
will blink red. The control will supply 80°F to the
floor/ emitter to keep the system from freezing.
■ SYSTEM — The mixed water temperature
that the Hydronic Mixing Block supplies. This
symbol: ----- present in the field means the
sensor is bad or the wire is broken or shorted.
■ OUTDOOR — The outdoor temperature as
read by the outdoor sensor.
■ PRESSURE — The system pressure is read
by the temperature/pressure sensor located
to the left of the display screen. The number
displayed in this field is the system pressure.
If the words LOW are present in the pressure
field for one minute, the control will shut off
to prevent damage. If the symbol: ----- is
present, it indicates the sensor is bad or the
wire is broken or shorted.
■ VALVE POSITION — Identifies the position of
the internal valve.
■ BOILER PROTECT — If the display screen
is yellowish/green and BOILER PROTECT
is present in the lower left and right of the
screen, the boiler is in protection mode.
Screen Color Indicator Status
Light Blue/Gray No Heat Demand
Solid Red Heat demand, boiler running
Yellow/Green Heat demand, boiler running but in boiler protection mode
Dark Blue Heat demand, boiler satisfied
Blinking Red
Failed boiler sensor or broken/shorted wire. Under this condition the block
will supply 80°F fluid to the floor/emitter to keep the system from freezing
Blinking Purple PURGE MODE, will open valve for 30 min duration to allow for purging