The bypass port maintains a minimum flame even when the main valve is closed.
The (often branded under Robertshaw as the VC4200 series ) is a mechanical, heavy-duty commercial gas thermostat primarily used for high-capacity cooking equipment like deck ovens, pizza ovens, and convection ranges . Unlike modern residential digital thermostats, this model uses a throttling mechanism to provide precise temperature regulation for gas appliances. Key Specifications & Features Application : Designed for commercial gas-fired equipment. Invensys Thermostat Manual Model Fd
: Ensure the red button is held down for at least one minute after lighting to engage the thermocouple. The bypass port maintains a minimum flame even
For detailed installation diagrams, you can refer to the Robertshaw VC4200 Commercial Installation Guide or the Invensys Heating and Cooling Basics Manual . Key Specifications & Features Application : Designed for
: If you have a digital Invensys model (like the 9000 series) rather than the mechanical FD, "LO" typically indicates a low battery or that the room temperature is below 30°F.
To adjust: light the main burner and set the dial to 300°F. Once the temperature is constant, turn the dial back to the lowest setting.
Because this model is entirely mechanical, adjustments are physical rather than digital. :