User Guide

23
Service Manual NeoTherm 80 - NeoTherm 285
Testing the Flow Switch
The ow switch uses a set of paddles to sense water
owing through the system. See Fig. B9-1. When
water is owing, the switch is normally closed (N.C.).
If the water ow stops, the switch opens. After a “no
ow” condition, the switch resets itself immediately
and automatically.
Use a volt-ohmmeter to test the continuity through
the switch. With the paddles in the “relaxed” position
(standing upright), the switch should be open. Bend
the paddles slightly to one side, and you should see
the switch close.
Note - There is a seal at the base of the paddle as-
sembly. If this seal fails, it can allow water to leak
into the connection box. From there, the water can
ow through conduits to other parts of the control
system in the NeoTherm unit.
If it is necessary to replace the ow switch, see Sec-
tion B10 for instructions.
Fig. B9-1 – Typical ow switch
B9