Xylem MOH2 Multi zone mixing module (obsolete) - Manual (Page 6)

6
Installation and operation manual MOH2
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Presetting knob for control valve
• The control valve is equipped with a presetting knob 5, with which the
maximum amount of water from the boiler loop can be reduced. The
unit is shipped with the presetting knob completely open.
Bypass for step-down control
• If the bypass valve 6 is opened, a small quantity of boiler feed water will
run constantly through the mixing module. This is necessary for a step-
down control, which derives its outside temperature information from
the boiler feed temperature. The unit is shipped with the bypass valve
opened 1/2 turn.
Fill and drain valves
• If you fill the system from the fill valve 12, the check valve 7 will close.
In this way, the water will flow through the floor heating loops and not
through the mixing module. Excess water drains through the drain valve
13.
Sensor positions integrated in the base module
• Floor heating feed temperature 14
• Floor heating return temperature 15
• Safety temperature 16
• Boiler feed temperature 17
• Dip tube for calorimeter sensor 18
Attaching a manifold to the MOH2 to base module
Attaching a Laing segmented plastic manifold
• Attach the manifolds before mounting the module.
• Attach manifolds directly to the flanges of the MOH2
• Adjusts the length of the threaded rods according to the number of zones
• Screw the threaded rods into the MOH2
• If the manifolds should be offset, use one or two 20 mm spacers on the
feed or return side
• Insert the red segments on the feed side [top], the blue segments on
the return side (bottom) onto the threaded rods. Caution: make sure
that the seal surfaces and seal rings are free of dirt.
• Close manifolds with end plate (caution: plastic cover must face the
water) and tighten the nuts evenly.