6.0SERVICE (Continued)
RE-ESTABLISHING VACUUM
Periodically check pressure gauge when kettle is cold. Reading should be in green vacuum zone (below 0 psi). Otherwise air is present and proper heating will not occur. Use the following procedure to remove air and
With the kettle empty, turn the thermostat knob to the highest temperature. When the pressure gauge reaches 20 psi, turn thermostat off, open the pressure relief valve until pressure gauge reads 1 psi, then sharply release it. This should remove the air and restore performance of the kettle.
Should the kettle fail to maintain a vacuum after repeated attempts to establish vacuum, further checks should be made to see if the pressure relief valve is leaking or if there are any leaks in the pressure relief valve piping, copper lines going to the pressure switch, pressure gauge or thermostat fitting.
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