Laars NEOTHERM NTV, Service Manual

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20
Service Manual - NeoTherm 500
Removing and Replacing the Low Water Cutoff Controls
The low water cutoff (LWCO) is designed to shut down
the unit if there is a low water condition. The control
includes two parts: a control box, and a probe which
reaches into the water piping.
Tools and equipment required:
• Small Phillips-head screwdriver (#1)
• Two medium-sized pipe wrenches or adjustable
wrenches
• 5/16” socket
Procedure - Removing or replacing the probe
1. Turn off power to the system. Use the main discon-
nect switch on the front panel.
2. Isolate the boiler. Turn off the water shutoff valves
located upstream and downstream of the unit.
3. Drain the boiler.
4. Unlock and open the front panels on the unit. Turn
the two wingnuts and swing out the center electrical
panel. Now you will have easy access to the probe,
as shown in Fig. B6-1.
5. Disconnect the probe wire and the ground wire.
6. Use two pipe wrenches to unscrew the probe as-
sembly. Turn the probe assembly counter-clockwise
to loosen it.
7. To reassemble, reverse the procedure we have just
described. Keep these points in mind as you do this:
• Use pipe dope on the threads on the probe as -
sembly.
• Be sure the wiring connections are tight.
Fig. B6-1 - Removing the probe for the low water cutoff
B6