LAARS NeoTherm NTV (Sizes 399-850 MBTU/h) - Service Manual - Manual (Page 43)

33
Service Manual - NeoTherm 500
Removing and Replacing the High and Low
Gas Pressure Switches (continued)
B15
cont.
Procedure - Removing or replacing either switch
1. Turn off power to the machine. Use the main discon-
nect switch on the front of the machine, just above
the control panel.
2. Remove the front panel.
3. Shut off the gas at the gas shutoff valve on the right
side of the machine (yellow handle).
4. Disconnect the wires to the gas pressure switch.
Remove the front cover on the gas switch by remov-
ing the two screws. Before disconnecting the wires,
note the way they are connected to the switch.
Fig. B15-2 - Gas shutoff valve (typical)
Fig. B15-3 - High gas pressure switch - cover removed
For the high gas pressure switch only -
Mark the wire on the left using a piece of
electrical tape. When the switch is assem-
bled, this wire will go to the “N.C.” connec-
tion.
Wire to N.C.
contact
Mark this
wire with a
piece of tape.
Set to
3” w.c.