Noritz N-0841MC Series Manual page 4

Procedure
(2) Left Side Wiring Harness: Thermal fuse
(2), Freeze prevention heaters (2),
Neutralizer sensor plug
(3) Right Side Wiring Harness: High limit
switch (2), Freeze prevention
heater(2), Freeze prevention sensor
(4) Flame rods (2), ignition box
(5) Left Side On Stainless Steel Heat
Exchanger(aka SS HE): Freeze
prevention sensor (take off whole clip)
(6) Right Side On SS HE: Freeze prevention
sensor plugs (2)
Diagram
Page 4