OEM Goodman 300°F Manual Reset Rollout Switch for GMTH045-3B — B1370145

OEM Goodman B1370145 Flame Rollout Switch (300°F)

The Goodman B1370145 is a genuine 300°F manual-reset flame rollout switch for GMTH045-3B gas furnaces and compatible Goodman/Amana models. This critical safety limit mounts near the burner box and opens the control circuit if flames roll out of the burner area — typically from a blocked heat exchanger, cracked exchanger, or restricted venting. When it trips, the furnace locks out on a hard fault until the cause is corrected and the button is manually reset.

Specifications

• Trip temperature: 300°F (manual reset)
• OEM Part Number: B1370145
• Fits: Goodman GMTH045-3B and cross-compatible furnace models
• Application: Flame rollout safety limit
• Type: Normally-closed, opens on temperature rise

OEM vs. Generic

A rollout switch is a life-safety device — its trip point and reset behavior must match the furnace design exactly. Genuine Goodman OEM guarantees the correct 300°F setpoint and mounting fit. Never substitute a switch with a different temperature rating or bypass a tripped rollout; doing so defeats a safety that protects against combustion escaping the burner box.

Installation Difficulty: Easy

Rated Easy for a qualified technician, but the diagnosis is the important part. Cut power, note and transfer the wire leads, unscrew the old switch from its bracket, and mount the new one in the same position. Critically, always identify and correct why the rollout tripped — check the heat exchanger and venting — before restoring the furnace to service.