LAARS NeoTherm NTV (Sizes 150–285 MBTU/h) - Service Manual - Manual (Page 36)

26
Service Manual NeoTherm 80 - NeoTherm 285
Removing and Replacing the Gas Valve
The modulating gas valve consists of a valve body that controls the on/off
gas flow and a negative pressure regulator. It provides the air/gas ratio
control in combination with the Venturi to the unit.
The easiest way to remove the gas valve is to remove the air/gas channel
and blower as one assembly, then separate the gas valve from the as-
sembly. Because of the way the gas valve is mounted in the machine, it
would be very difficult to remove the gas valve from the machine directly.
Figure B11-1 shows how the parts are arranged.
Tools and equipment required:
• 3 mm and 4 mm Allen wrenches
(traditional “L” shaped, ball-head is
best)
• #25 Torx® driver
• Gas-resistant pipe dope or Tef-
lon® tape
• Gas leak detection solution (i.e.
Hercules Megabubble®)
• Container for removed parts
Gas valve
Rubber inlet
hose
Air/gas channel
Blower
Fig. B11-1 - Gas valve and other parts - NT105 shown
Procedure:
1. Turn off power to the machine. Use the main
disconnect 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).
Fig. B11-2 - Gas shutoff valve (typical)
B11