PRO 1 IAQ T501ML4 4-Wire Mechanical Line Voltage Thermostat Heat Only

The PRO 1 IAQ T501ML4 Mechanical Line Voltage Thermostat 4-Wire Heat Only is a non-programmable control part used to regulate electric heating loads by switching power on or off based on room temperature. It operates through a bimetal sensing element that expands and contracts with changes, activating internal contacts to maintain a fixed setpoint. Commonly installed in electric baseboard heaters, wall-mounted heaters, and similar resistive setups within HVAC systems, it is mounted on a wall or junction box for direct wiring. This unit provides steady temperature control, simple dial adjustment, and consistent operation for single-stage applications.