Whirlpool 4322452 Service Manual page 46

The Thermostat is a hydraulic valve that has two separate gas lines and a sensing bulb (see
Figure 4-2 ). The pilot gas line maintains a pilot flame in the oven, and the main gas line provides
gas to the oven safety valve. The sensing bulb is a mercury-filled tube that controls the thermostat
to open or close the gas lines, and release gas from the manifold pipe to the oven safety valve. The
thermostat operates based on the temperature it senses in the oven cavity.
Sensing Bulb &
Capillary Tube
The Oven Safety Valve is also a hydraulic valve that has a gas inlet line and a gas port that is
metered by an orifice hood (see Figure 4-3). It also has a mercury-filled sensing bulb that controls
its operation. The safety valve has one function: to release gas to the oven burner from the
thermostat.
Heater Sensing
Bulb & Capillary Tube
Cold Sensor
Figure 4-2
Orifice Hood
Safety Valve
Figure 4-3
Page 4-2
Manifold
Gas In
T
O
F A
F
N
P
L
Oven
Thermostat
Valve Closed
No Gas Flow
Gas Inlet
(From Thermostat)