AMERICAN RANGE - CALIBRATING BJ THERMOSTAT

Summary

This video tutorial provides step-by-step instructions for calibrating and adjusting a BJ thermostat on a standard oven. It covers lighting the pilot, checking bypass temperatures using the right tools, and adjusting the bypass screw to ensure the oven maintains accurate temperatures. The video emphasizes the importance of fine-tuning the thermostat dial without turning the internal screw to avoid damage. It also mentions that calibrations are not covered under warranty and highlights the need for bypass adjustments if converting between natural gas and LP gas. The video concludes with tips for optimal thermostat performance.

Takeaways

• 😀 Light the pilot and fire up the oven to check bypass temperatures. A Mercury oven thermometer or digital pyrometer should be used for accurate readings, avoiding infrared or laser guns.
• 😀 The oven should heat at full temperature and burner speed. As it approaches the set temperature, the flame will gradually decrease in size until it reaches the bypass flame.
• 😀 The bypass flame is a minimal holding flame, around an eighth of an inch tall. It should maintain the set temperature within a 2-3 degree margin.
• 😀 If the bypass flame needs adjustment, remove the front panel and use the bypass screw. Adjust the flame to about an eighth of an inch tall, ensuring proper temperature control.
• 😀 Once the bypass is set, avoid further calibration attempts unless necessary. Accuracy should be within a 2-3 degree range of the set temperature.
• 😀 The bypass screw is very fine-tuned and should not be turned. Instead, hold the screw and rotate the thermostat dial to match the oven's temperature.
• 😀 Do not turn the central screw too far, as it can break the thermostat by damaging the internal mechanism connected to the diaphragm.
• 😀 Thermostats are most accurate in the center of their range (200-500°F), with optimal calibration occurring between 300-350°F.
• 😀 Calibrations and adjustments are not covered under warranty, as they are part of appliance maintenance and setup.
• 😀 If the oven undergoes a gas conversion (e.g., from natural gas to LP), the bypass setting will need to be recalibrated to match the new gas type for proper operation.

Q & A

What is the first step when calibrating a BJ thermostat on a standard oven?

The first step is to light the pilot and fire up the oven to check the bypass temperatures.

What temperature should the bypass be calibrated to?

The bypass should be calibrated to 300°F.

What type of thermometer should be used to check the oven temperature?

A Mercury oven thermometer or a digital pyrometer should be used. Laser or infrared guns are not recommended.

What happens to the burner flame as the oven approaches the set temperature?

The burner flame gradually decreases in size until it reaches the bypass flame, which is a minimal holding flame.

How tall should the bypass flame be when properly adjusted?

The bypass flame should be about an eighth of an inch tall.

What should you do if the bypass needs adjustment?

You should remove the front panel and adjust the bypass screw, ensuring that the flame remains at approximately an eighth of an inch tall.

What is the accuracy range for BJ thermostats?

The accuracy of these thermostats is approximately 20 to 25 degrees Fahrenheit.

How do you adjust the thermostat dial after setting the bypass flame?

To adjust the thermostat dial, hold the screw at the back of the knob, rotate the knob to the reading in the oven, but do not turn the screw itself.

Why should you avoid turning the screw when adjusting the thermostat dial?

Turning the screw could damage the thermostat internally, rendering it inoperable.

What is the recommended temperature range for optimal thermostat operation?

The most accurate operation occurs in the center of the thermostat's range, which is between 300°F and 350°F.

What should be done if the oven undergoes a gas conversion (e.g., from natural to LP)?

The bypass needs to be reset according to the new gas type for the oven to operate correctly after the conversion.